diff --git a/Tests/CoreTests/FrameCodecTests.swift b/Tests/CoreTests/FrameCodecTests.swift
new file mode 100644
index 0000000..21d785d
--- /dev/null
+++ b/Tests/CoreTests/FrameCodecTests.swift
@@ -0,0 +1,247 @@
+// FrameCodecTests.swift
+// Unit tests for BinaryFrame, ClientToServer encoding, and ServerToClient decoding.
+//
+// All tests are pure (no network, no Starscream, no async).  FrameCodec.swift
+// imports only Foundation, making this test target dependency-free.
+//
+// IC-1 spec reference: docs/PHASE-2-ios-mvp.md §Wire Protocol
+
+import XCTest
+@testable import piRemote
+
+final class FrameCodecTests: XCTestCase {
+
+    // =========================================================================
+    // MARK: 1. BinaryFrame.decode
+    // =========================================================================
+
+    /// Well-formed binary frame: 8-byte big-endian seq = 1, payload = "hello".
+    func testBinaryFrameDecode_knownBytes() throws {
+        // seq = 1 in big-endian: 00 00 00 00 00 00 00 01
+        let seqBytes: [UInt8] = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01]
+        let payload   = Array("hello".utf8)
+        let raw       = Data(seqBytes + payload)
+
+        let frame = try XCTUnwrap(BinaryFrame.decode(raw))
+        XCTAssertEqual(frame.seq,  1)
+        XCTAssertEqual(frame.data, Data("hello".utf8))
+    }
+
+    /// UInt64.max must round-trip through the 8-byte big-endian header.
+    func testBinaryFrameDecode_maxSeq() throws {
+        let seqBytes: [UInt8] = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]
+        let raw = Data(seqBytes) // empty payload is valid
+
+        let frame = try XCTUnwrap(BinaryFrame.decode(raw))
+        XCTAssertEqual(frame.seq, UInt64.max)
+        XCTAssertTrue(frame.data.isEmpty)
+    }
+
+    /// seq = 0x0000_0001_0000_0000 = 4_294_967_296 verifies big-endian byte order.
+    func testBinaryFrameDecode_bigEndianOrdering() throws {
+        let seqBytes: [UInt8] = [0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00]
+        let raw = Data(seqBytes + [0xAB, 0xCD])
+
+        let frame = try XCTUnwrap(BinaryFrame.decode(raw))
+        XCTAssertEqual(frame.seq,  4_294_967_296)
+        XCTAssertEqual(frame.data, Data([0xAB, 0xCD]))
+    }
+
+    /// Frames shorter than 8 bytes must return nil (header incomplete).
+    func testBinaryFrameDecode_tooShort_returnsNil() {
+        XCTAssertNil(BinaryFrame.decode(Data([0x00, 0x01, 0x02])))
+    }
+
+    /// Empty data must also return nil (0 bytes < 8-byte minimum).
+    func testBinaryFrameDecode_emptyData_returnsNil() {
+        XCTAssertNil(BinaryFrame.decode(Data()))
+    }
+
+    /// Exactly 8 bytes is valid: empty payload, seq extracted from header.
+    func testBinaryFrameDecode_exactlyEightBytes_emptyPayload() throws {
+        // seq = 42 = 0x2A
+        let seqBytes: [UInt8] = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2A]
+        let frame = try XCTUnwrap(BinaryFrame.decode(Data(seqBytes)))
+        XCTAssertEqual(frame.seq, 42)
+        XCTAssertTrue(frame.data.isEmpty)
+    }
+
+    // =========================================================================
+    // MARK: 2. ClientToServer JSON encoding — IC-1 field names
+    // =========================================================================
+
+    func testEncode_resume_nilLastSeq_producesNull() throws {
+        // IC-1 requires {"type":"resume","lastSeq":null}
+        let json = try FrameCodec.encode(.resume(lastSeq: nil))
+        let obj  = try asDict(json)
+        XCTAssertEqual(obj["type"] as? String, "resume", "type field must be 'resume'")
+        XCTAssertTrue(obj["lastSeq"] is NSNull,
+                      "lastSeq must be JSON null, got: \(String(describing: obj["lastSeq"]))")
+    }
+
+    func testEncode_resume_withLastSeq42() throws {
+        // IC-1 requires {"type":"resume","lastSeq":42}
+        let json = try FrameCodec.encode(.resume(lastSeq: 42))
+        let obj  = try asDict(json)
+        XCTAssertEqual(obj["type"]    as? String, "resume")
+        XCTAssertEqual(obj["lastSeq"] as? Int,    42)
+    }
+
+    func testEncode_key_escape() throws {
+        // IC-1 requires {"type":"key","name":"escape"}
+        let json = try FrameCodec.encode(.key(name: "escape"))
+        XCTAssertEqual(json, #"{"type":"key","name":"escape"}"#,
+                       "Exact IC-1 encoding expected")
+    }
+
+    func testEncode_keys_data() throws {
+        // IC-1 requires {"type":"keys","data":"hello"}
+        let json = try FrameCodec.encode(.keys(data: "hello"))
+        let obj  = try asDict(json)
+        XCTAssertEqual(obj["type"] as? String, "keys")
+        XCTAssertEqual(obj["data"] as? String, "hello")
+    }
+
+    func testEncode_paste_data() throws {
+        // IC-1 requires {"type":"paste","data":"text"}
+        let json = try FrameCodec.encode(.paste(data: "text"))
+        let obj  = try asDict(json)
+        XCTAssertEqual(obj["type"] as? String, "paste")
+        XCTAssertEqual(obj["data"] as? String, "text")
+    }
+
+    func testEncode_snapshotRequest() throws {
+        // IC-1 requires {"type":"snapshot-request"}
+        let json = try FrameCodec.encode(.snapshotRequest)
+        XCTAssertEqual(json, #"{"type":"snapshot-request"}"#,
+                       "Exact IC-1 encoding expected")
+    }
+
+    /// Multi-line paste must survive encoding without key truncation.
+    func testEncode_paste_multilineData() throws {
+        let json = try FrameCodec.encode(.paste(data: "line1\nline2"))
+        let obj  = try asDict(json)
+        XCTAssertEqual(obj["data"] as? String, "line1\nline2")
+    }
+
+    // =========================================================================
+    // MARK: 3. ServerToClient JSON decoding
+    // =========================================================================
+
+    func testDecode_state_idle() throws {
+        let payload = #"{"type":"state","value":"idle","ts":1716000000}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .state(let value, let tool, let ts) = frame else {
+            return XCTFail("Expected .state, got \(frame)")
+        }
+        XCTAssertEqual(value, .idle)
+        XCTAssertNil(tool)
+        XCTAssertEqual(ts, 1_716_000_000)
+    }
+
+    func testDecode_state_thinking() throws {
+        let payload = #"{"type":"state","value":"thinking","ts":1}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .state(let value, _, _) = frame else {
+            return XCTFail("Expected .state, got \(frame)")
+        }
+        XCTAssertEqual(value, .thinking)
+    }
+
+    func testDecode_state_tool_withToolName() throws {
+        let payload = #"{"type":"state","value":"tool","tool":"bash","ts":42}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .state(let value, let tool, let ts) = frame else {
+            return XCTFail("Expected .state, got \(frame)")
+        }
+        XCTAssertEqual(value, .tool)
+        XCTAssertEqual(tool,  "bash")
+        XCTAssertEqual(ts,    42)
+    }
+
+    func testDecode_state_awaitingInput() throws {
+        // IC-1 raw value is "awaiting-input" (hyphenated)
+        let payload = #"{"type":"state","value":"awaiting-input","ts":0}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .state(let value, _, _) = frame else {
+            return XCTFail("Expected .state, got \(frame)")
+        }
+        XCTAssertEqual(value, .awaitingInput,
+                       "PiState must map 'awaiting-input' → .awaitingInput")
+    }
+
+    func testDecode_snapshot() throws {
+        let payload = #"{"type":"snapshot","seq":1234,"data":"SGVsbG8="}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .snapshot(let seq, let data) = frame else {
+            return XCTFail("Expected .snapshot, got \(frame)")
+        }
+        XCTAssertEqual(seq,  1234)
+        XCTAssertEqual(data, "SGVsbG8=")
+    }
+
+    func testDecode_sessionMeta_withDescription() throws {
+        let payload = #"{"type":"session-meta","name":"my-session","description":"A test session","createdAt":"2026-05-15T10:00:00Z"}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .sessionMeta(let name, let description, let createdAt) = frame else {
+            return XCTFail("Expected .sessionMeta, got \(frame)")
+        }
+        XCTAssertEqual(name,        "my-session")
+        XCTAssertEqual(description, "A test session")
+        XCTAssertEqual(createdAt,   "2026-05-15T10:00:00Z")
+    }
+
+    func testDecode_sessionMeta_withoutDescription() throws {
+        // description is optional per IC-1
+        let payload = #"{"type":"session-meta","name":"bare","createdAt":"2026-01-01T00:00:00Z"}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .sessionMeta(let name, let description, _) = frame else {
+            return XCTFail("Expected .sessionMeta, got \(frame)")
+        }
+        XCTAssertEqual(name, "bare")
+        XCTAssertNil(description)
+    }
+
+    func testDecode_error() throws {
+        let payload = #"{"type":"error","code":"auth_failed","message":"Invalid token"}"#
+        let frame   = try FrameCodec.decode(payload)
+        guard case .error(let code, let message) = frame else {
+            return XCTFail("Expected .error, got \(frame)")
+        }
+        XCTAssertEqual(code,    "auth_failed")
+        XCTAssertEqual(message, "Invalid token")
+    }
+
+    /// Unknown type keys must throw a `DecodingError`, not silently return garbage.
+    func testDecode_unknownType_throws() {
+        let payload = #"{"type":"tree","nodes":[]}"#
+        XCTAssertThrowsError(try FrameCodec.decode(payload),
+                             "Unknown type discriminator must throw")
+    }
+
+    /// Malformed JSON must throw.
+    func testDecode_malformedJSON_throws() {
+        XCTAssertThrowsError(try FrameCodec.decode("not json at all"))
+    }
+
+    // =========================================================================
+    // MARK: 4. Round-trip: encode ClientToServer → decode shape check
+    // =========================================================================
+
+    /// Encode a .key frame and verify it can be re-parsed by JSONSerialization.
+    func testRoundtrip_encode_isValidJSON() throws {
+        let json = try FrameCodec.encode(.key(name: "up"))
+        // Must not throw — i.e., the output is valid JSON.
+        XCTAssertNoThrow(try JSONSerialization.jsonObject(with: Data(json.utf8)))
+    }
+
+    // =========================================================================
+    // MARK: Helpers
+    // =========================================================================
+
+    private func asDict(_ json: String) throws -> [String: Any] {
+        let obj = try JSONSerialization.jsonObject(with: Data(json.utf8))
+        return try XCTUnwrap(obj as? [String: Any],
+                             "Expected top-level JSON object, got \(type(of: obj))")
+    }
+}
diff --git a/Tests/CoreTests/KeychainTests.swift b/Tests/CoreTests/KeychainTests.swift
new file mode 100644
index 0000000..14fe4f9
--- /dev/null
+++ b/Tests/CoreTests/KeychainTests.swift
@@ -0,0 +1,151 @@
+// KeychainTests.swift
+// Unit tests for the Keychain wrapper.
+//
+// IMPORTANT: Each test uses a unique key (never the production key
+// `Keychain.credentialKey`) so real app data is never touched.
+// All test keys are deleted in tearDown even if the test fails.
+//
+// Note: Keychain tests require the iOS simulator or a real device with
+// a valid entitlement.  They will fail in headless environments where
+// the Security framework is unavailable.
+
+import XCTest
+@testable import piRemote
+
+final class KeychainTests: XCTestCase {
+
+    // MARK: - Helpers
+
+    /// Unique per-run key prefix so parallel test runs don't collide.
+    private var testKey: String { "test.keychain.\(name)" }
+
+    override func tearDown() {
+        // Always clean up the test key to avoid polluting the Keychain.
+        Keychain.shared.delete(key: testKey)
+        super.tearDown()
+    }
+
+    /// A minimal `SidecarCredential` for testing.
+    private func makeCredential(name: String = "test-pi") -> SidecarCredential {
+        SidecarCredential(
+            sidecarId:      "sid-\(UUID().uuidString)",
+            host:           "192.168.1.100",
+            port:           7777,
+            bearerToken:    "bearer-\(UUID().uuidString)",
+            tlsFingerprint: "deadbeef1234",
+            sidecarName:    name,
+            pairedAt:       Date(timeIntervalSince1970: 1_716_000_000)
+        )
+    }
+
+    // =========================================================================
+    // MARK: 1. Save + load round-trip
+    // =========================================================================
+
+    func testSaveAndLoad_credential_roundTrips() throws {
+        let credential = makeCredential(name: "my-pi")
+
+        try Keychain.shared.save(credential, key: testKey)
+        let loaded: SidecarCredential = try Keychain.shared.load(key: testKey)
+
+        XCTAssertEqual(loaded.sidecarId,      credential.sidecarId)
+        XCTAssertEqual(loaded.host,           credential.host)
+        XCTAssertEqual(loaded.port,           credential.port)
+        XCTAssertEqual(loaded.bearerToken,    credential.bearerToken)
+        XCTAssertEqual(loaded.tlsFingerprint, credential.tlsFingerprint)
+        XCTAssertEqual(loaded.sidecarName,    credential.sidecarName)
+        // Date comparison within 1 second tolerance (JSON Date encoding).
+        XCTAssertEqual(loaded.pairedAt.timeIntervalSince1970,
+                       credential.pairedAt.timeIntervalSince1970,
+                       accuracy: 1.0)
+    }
+
+    // =========================================================================
+    // MARK: 2. Update (upsert)
+    // =========================================================================
+
+    func testSave_overwritesPrevious_onLoad() throws {
+        let first  = makeCredential(name: "first-pi")
+        let second = makeCredential(name: "second-pi")
+
+        try Keychain.shared.save(first,  key: testKey)
+        try Keychain.shared.save(second, key: testKey)
+
+        let loaded: SidecarCredential = try Keychain.shared.load(key: testKey)
+        XCTAssertEqual(loaded.sidecarName, "second-pi",
+                       "Second save must overwrite the first")
+    }
+
+    // =========================================================================
+    // MARK: 3. Missing key → notFound
+    // =========================================================================
+
+    func testLoad_missingKey_throwsNotFound() {
+        let missingKey = "test.keychain.definitely-absent-\(UUID())"
+        defer { Keychain.shared.delete(key: missingKey) }
+
+        XCTAssertThrowsError(try Keychain.shared.load(key: missingKey) as SidecarCredential) { error in
+            guard let keychainError = error as? KeychainError,
+                  case .notFound = keychainError else {
+                XCTFail("Expected KeychainError.notFound, got \(error)")
+                return
+            }
+        }
+    }
+
+    // =========================================================================
+    // MARK: 4. Delete clears entry
+    // =========================================================================
+
+    func testDelete_clearsEntry() throws {
+        try Keychain.shared.save(makeCredential(), key: testKey)
+
+        Keychain.shared.delete(key: testKey)
+
+        XCTAssertThrowsError(try Keychain.shared.load(key: testKey) as SidecarCredential,
+                             "After delete, load must throw") { error in
+            guard let keychainError = error as? KeychainError,
+                  case .notFound = keychainError else {
+                XCTFail("Expected KeychainError.notFound after delete, got \(error)")
+                return
+            }
+        }
+    }
+
+    func testDelete_missingKey_isNoOp() {
+        // Deleting a key that doesn't exist must not crash or throw.
+        Keychain.shared.delete(key: "test.keychain.never-saved-\(UUID())")
+        // No assertion needed — reaching this line means no crash.
+    }
+
+    // =========================================================================
+    // MARK: 5. Production key is NOT used in tests
+    // =========================================================================
+
+    func testProductionKeyIsUntouched() {
+        // This test simply verifies that our test key is different from the
+        // production credential key, so tests never corrupt real data.
+        XCTAssertNotEqual(testKey, Keychain.credentialKey,
+                          "Test key must differ from the production credential key")
+    }
+
+    // =========================================================================
+    // MARK: 6. Generic save/load with a simple Codable type
+    // =========================================================================
+
+    private struct TestPayload: Codable, Equatable {
+        let id:    String
+        let value: Int
+    }
+
+    func testSaveAndLoad_simplePayload() throws {
+        let key     = "test.keychain.payload.\(UUID())"
+        let payload = TestPayload(id: "x", value: 99)
+        defer { Keychain.shared.delete(key: key) }
+
+        try Keychain.shared.save(payload, key: key)
+        let loaded: TestPayload = try Keychain.shared.load(key: key)
+
+        XCTAssertEqual(loaded, payload)
+    }
+}
diff --git a/Tests/CoreTests/PairingTests.swift b/Tests/CoreTests/PairingTests.swift
new file mode 100644
index 0000000..34262b0
--- /dev/null
+++ b/Tests/CoreTests/PairingTests.swift
@@ -0,0 +1,160 @@
+// PairingTests.swift
+// Unit tests for PairingService.parseQR — IC-1 QR URL parsing.
+//
+// Format: pi-remote://<host>:<port>?pair=<pairingToken>&fp=<fingerprint>&name=<sidecarName>
+//
+// No network calls are made; parseQR is a pure function.
+
+import XCTest
+@testable import piRemote
+
+final class PairingTests: XCTestCase {
+
+    // =========================================================================
+    // MARK: 1. Happy-path parsing
+    // =========================================================================
+
+    func testParseQR_canonical_parsesAllFields() throws {
+        let url = "pi-remote://192.168.1.1:7777?pair=abc&fp=deadbeef&name=pi-remote"
+        let result = try PairingService.parseQR(url)
+
+        XCTAssertEqual(result.host,         "192.168.1.1")
+        XCTAssertEqual(result.port,         7777)
+        XCTAssertEqual(result.pairingToken, "abc")
+        XCTAssertEqual(result.fingerprint,  "deadbeef")
+        XCTAssertEqual(result.name,         "pi-remote")
+    }
+
+    func testParseQR_hostOnly_differentPort() throws {
+        let url = "pi-remote://pi.local:9000?pair=tok123&fp=aabbcc&name=mypi"
+        let result = try PairingService.parseQR(url)
+
+        XCTAssertEqual(result.host,         "pi.local")
+        XCTAssertEqual(result.port,         9000)
+        XCTAssertEqual(result.pairingToken, "tok123")
+        XCTAssertEqual(result.fingerprint,  "aabbcc")
+        XCTAssertEqual(result.name,         "mypi")
+    }
+
+    func testParseQR_longFingerprint_parsedCorrectly() throws {
+        let fp  = String(repeating: "a1", count: 32) // 64-char SHA-256 hex
+        let url = "pi-remote://10.0.0.1:7777?pair=t&fp=\(fp)&name=n"
+        let result = try PairingService.parseQR(url)
+        XCTAssertEqual(result.fingerprint, fp)
+    }
+
+    func testParseQR_portBoundary_lowPort() throws {
+        let url = "pi-remote://localhost:1?pair=t&fp=f&name=n"
+        let result = try PairingService.parseQR(url)
+        XCTAssertEqual(result.port, 1)
+    }
+
+    func testParseQR_portBoundary_highPort() throws {
+        let url = "pi-remote://localhost:65535?pair=t&fp=f&name=n"
+        let result = try PairingService.parseQR(url)
+        XCTAssertEqual(result.port, 65535)
+    }
+
+    func testParseQR_nameWithSpaces_percentEncoded() throws {
+        // Spaces encoded as %20 in the QR URL
+        let url = "pi-remote://192.168.1.1:7777?pair=tok&fp=fp&name=my%20pi"
+        let result = try PairingService.parseQR(url)
+        XCTAssertEqual(result.name, "my pi")
+    }
+
+    // =========================================================================
+    // MARK: 2. Missing required parameters → throws
+    // =========================================================================
+
+    func testParseQR_missingPairParam_throws() {
+        let url = "pi-remote://192.168.1.1:7777?fp=deadbeef&name=pi-remote"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "Missing 'pair' must throw")
+    }
+
+    func testParseQR_missingFpParam_throws() {
+        let url = "pi-remote://192.168.1.1:7777?pair=abc&name=pi-remote"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "Missing 'fp' must throw")
+    }
+
+    func testParseQR_missingNameParam_throws() {
+        let url = "pi-remote://192.168.1.1:7777?pair=abc&fp=deadbeef"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "Missing 'name' must throw")
+    }
+
+    func testParseQR_noQueryParams_throws() {
+        let url = "pi-remote://192.168.1.1:7777"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "No query params must throw")
+    }
+
+    func testParseQR_emptyPairValue_throws() {
+        let url = "pi-remote://192.168.1.1:7777?pair=&fp=deadbeef&name=pi-remote"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "Empty 'pair' value must throw")
+    }
+
+    // =========================================================================
+    // MARK: 3. Wrong scheme → throws
+    // =========================================================================
+
+    func testParseQR_httpsScheme_throws() {
+        // Wrong scheme — sidecar only issues pi-remote:// URLs
+        let url = "https://192.168.1.1:7777?pair=abc&fp=deadbeef&name=pi-remote"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "https:// scheme must throw .invalidQR")
+    }
+
+    func testParseQR_httpScheme_throws() {
+        let url = "http://192.168.1.1:7777?pair=abc&fp=deadbeef&name=pi-remote"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "http:// scheme must throw .invalidQR")
+    }
+
+    func testParseQR_emptyString_throws() {
+        XCTAssertThrowsError(try PairingService.parseQR(""),
+                             "Empty string must throw")
+    }
+
+    func testParseQR_randomString_throws() {
+        XCTAssertThrowsError(try PairingService.parseQR("not-a-url"),
+                             "Garbage string must throw")
+    }
+
+    // =========================================================================
+    // MARK: 4. Missing port → throws
+    // =========================================================================
+
+    func testParseQR_missingPort_throws() {
+        // No port specified — should throw because port is required
+        let url = "pi-remote://192.168.1.1?pair=abc&fp=deadbeef&name=pi-remote"
+        XCTAssertThrowsError(try PairingService.parseQR(url),
+                             "Missing port must throw .invalidQR")
+    }
+
+    // =========================================================================
+    // MARK: 5. Error type is PairingError.invalidQR
+    // =========================================================================
+
+    func testParseQR_wrongScheme_throwsInvalidQR() {
+        XCTAssertThrowsError(try PairingService.parseQR("https://host:7777?pair=x&fp=y&name=z")) { error in
+            guard let pairingError = error as? PairingError,
+                  case .invalidQR = pairingError else {
+                XCTFail("Expected PairingError.invalidQR, got \(error)")
+                return
+            }
+        }
+    }
+
+    func testParseQR_missingParam_throwsInvalidQR() {
+        XCTAssertThrowsError(try PairingService.parseQR("pi-remote://host:7777?pair=x&fp=y")) { error in
+            guard let pairingError = error as? PairingError,
+                  case .invalidQR = pairingError else {
+                XCTFail("Expected PairingError.invalidQR, got \(error)")
+                return
+            }
+        }
+    }
+}
diff --git a/Tests/CoreTests/REVIEW_NOTES.md b/Tests/CoreTests/REVIEW_NOTES.md
new file mode 100644
index 0000000..409a232
--- /dev/null
+++ b/Tests/CoreTests/REVIEW_NOTES.md
@@ -0,0 +1,172 @@
+# Phase 2 Implementation Review Notes
+
+**Reviewer:** T-2.1/2.2/2.3 Test Agent  
+**Date:** 2026-05-15  
+**Branch read:** `origin/feat/p2-t2-1-websocket`, `origin/feat/p2-t2-2-pairing`, `origin/feat/p2-t2-3-terminal`
+
+---
+
+## Branch Status at Discovery
+
+| Branch | Appeared at attempt | Files |
+|--------|---|---|
+| `feat/p2-t2-2-pairing` | Attempt 1 (~0 min) | **EMPTY** — only base scaffold |
+| `feat/p2-t2-3-terminal` | Attempt 10 (~4.5 min) | Terminal + Auth (both T-2.2 and T-2.3 files) |
+| `feat/p2-t2-1-websocket` | Attempt 13 (~6 min) | Network layer + partial FrameCodecTests |
+
+---
+
+## Implementation Summary
+
+### `feat/p2-t2-1-websocket` — Network Layer
+
+**Files:**
+- `Sources/Core/Network/FrameCodec.swift` — BinaryFrame, ClientToServer, ServerToClient, FrameCodec namespace
+- `Sources/Core/Network/ResumeCursor.swift` — UserDefaults-backed UInt64 cursor
+- `Sources/Core/Network/WebSocketClient.swift` — @MainActor Starscream wrapper with Combine subjects
+- `Tests/CoreTests/FrameCodecTests.swift` — Partial test file committed to this branch
+
+**Quality:** High. IC-1 wire format is faithfully implemented. All JSON field names match the spec. BinaryFrame.decode correctly uses big-endian byte shifting.
+
+### `feat/p2-t2-2-pairing` — EMPTY
+
+This branch contains **no implementation files** — only the base Xcode scaffold. The pairing code was found on `feat/p2-t2-3-terminal` instead (see below).
+
+### `feat/p2-t2-3-terminal` — Terminal + Auth (both T-2.2 and T-2.3)
+
+**Files:**
+- `Sources/Core/Auth/Keychain.swift` — Generic Codable Keychain wrapper
+- `Sources/Core/Auth/Pairing.swift` — PairingService with parseQR and exchange
+- `Sources/Core/Auth/SidecarCredential.swift` — Codable credential model
+- `Sources/UI/Pairing/PairingFlowView.swift` — SwiftUI pairing flow
+- `Sources/UI/Pairing/QRScannerView.swift` — AVFoundation QR scanner
+- `Sources/UI/Terminal/TerminalTheme.swift` — ThemeColor + TerminalTheme + built-ins
+- `Sources/UI/Terminal/ThemeStore.swift` — @MainActor ObservableObject
+- `Sources/UI/Terminal/FontStore.swift` — @MainActor ObservableObject
+- `Sources/UI/Terminal/TerminalFont.swift` — Static font presets
+- `Sources/UI/Terminal/TerminalViewController.swift` — SwiftTerm wrapper
+- `Sources/UI/Terminal/TerminalViewRepresentable.swift` — UIViewControllerRepresentable
+
+**Quality:** High. All types are Sendable-annotated correctly.
+
+---
+
+## IC-1 Compliance Issues
+
+### ✅ All Field Names Correct
+
+Every JSON field name in `FrameCodec.swift` matches IC-1:
+
+| Frame | Type field | Extra fields | Status |
+|-------|-----------|--------------|--------|
+| resume | `"resume"` | `lastSeq` (null or UInt64) | ✅ |
+| key | `"key"` | `name` | ✅ |
+| keys | `"keys"` | `data` | ✅ |
+| paste | `"paste"` | `data` | ✅ |
+| snapshot-request | `"snapshot-request"` | none | ✅ |
+| state (server) | `"state"` | `value`, `tool?`, `ts` | ✅ |
+| snapshot (server) | `"snapshot"` | `seq`, `data` | ✅ |
+| session-meta (server) | `"session-meta"` | `name`, `description?`, `createdAt` | ✅ |
+| error (server) | `"error"` | `code`, `message` | ✅ |
+
+### ✅ `awaiting-input` Raw Value Correct
+
+`PiState.awaitingInput` has `rawValue = "awaiting-input"` (hyphenated), which is correct per IC-1. This is a common mistake point — the implementation got it right.
+
+### ✅ `lastSeq: null` Encoding
+
+`ClientToServer.resume(lastSeq: nil)` explicitly encodes JSON `null` (not omitting the key), which is what IC-1 requires. The comment in the code explains this intentional choice.
+
+---
+
+## Swift 6 Concurrency Issues
+
+### ⚠️ Minor: `FrameCodec.encoder/decoder` — static mutable-ish singletons
+
+```swift
+// FrameCodec.swift
+private static let encoder: JSONEncoder = { ... }()
+private static let decoder = JSONDecoder()
+```
+
+`JSONEncoder` and `JSONDecoder` conform to `Sendable` as of Swift 5.7/Foundation updates. These are `static let` (not `var`), so they are initialized once and never mutated. **No Swift 6 compile error is expected.** However, if the Foundation version on the CI runner predates the `Sendable` conformance, a warning may appear. Recommend verifying with `-strict-concurrency=complete` on the build server.
+
+### ⚠️ `WebSocketClient` — `DelegateAdapter.owner` is a non-isolated var
+
+From the partial view of `WebSocketClient.swift`:
+
+```swift
+private let delegateAdapter = DelegateAdapter()
+// ...
+delegateAdapter.owner = self  // set in init
+```
+
+If `DelegateAdapter` stores `owner` as `weak var owner: WebSocketClient?` (not actor-isolated), and Starscream calls the delegate from a background thread, there could be a data race in Swift 6. The comment says callbacks are hopped through `Task { @MainActor in … }` but `owner` assignment itself may not be safe. **Needs audit** when the full file is reviewed during PR.
+
+### ✅ `ThemeStore` and `FontStore` — `@MainActor` Correct
+
+Both stores are `@MainActor final class ObservableObject`. Singleton access via `.shared` from non-actor-isolated contexts will require `await` in Swift 6. Tests in this repo mark their ThemeStore test functions with `@MainActor` to handle this correctly.
+
+### ✅ `PairingService` — `Sendable` Struct
+
+`PairingService` is a `struct Sendable`, and `parseQR` is a `static` function. No concurrency issues.
+
+### ✅ `Keychain` — `final class Sendable`
+
+The implementation declares `final class Keychain: Sendable`. Since all methods delegate to thread-safe `Security` framework APIs and there is no mutable stored state, this is correct. No issues.
+
+### ⚠️ `Keychain.load` throws `.encodingFailed` on decode failure
+
+```swift
+} catch {
+    throw KeychainError.encodingFailed  // misleading name
+}
+```
+
+The error case `KeychainError.encodingFailed` is thrown when **decoding** fails (reading from Keychain, not writing). The name is misleading — it should ideally be `.decodingFailed`. This is a minor naming issue, not a correctness problem, but callers that pattern-match `.encodingFailed` might be confused.
+
+---
+
+## Structural Issues
+
+### 🚨 `feat/p2-t2-2-pairing` Branch is Empty
+
+The T-2.2 pairing agent pushed a branch with no implementation files. The Auth and Pairing UI code was implemented by the T-2.3 terminal agent instead. This means:
+
+1. The pairing branch PR will be empty/trivially mergeable.
+2. The terminal branch PR contains code for both T-2.2 and T-2.3.
+3. **Recommendation:** Credit the terminal agent with T-2.2 work, or have the pairing agent cherry-pick the Auth files before their PR is reviewed.
+
+### ⚠️ `TerminalFont` is not `Equatable`
+
+`TerminalFont` is `Identifiable, Sendable` but **not `Equatable`**. This makes it harder to assert equality in tests and may cause issues if SwiftUI `ForEach` needs to diff fonts. Recommend adding `Equatable` conformance (or at least equality on `id`).
+
+### ⚠️ `JetBrains Mono` font not yet bundled
+
+Documented in the source (`T-2.12 deferred`). Tests must not assume `UIFont(name: "JetBrainsMono-Regular", size:)` succeeds — the fallback to system monospace is correct behavior for now.
+
+---
+
+## Recommendations for Merge Order
+
+1. **`feat/p2-t2-1-websocket`** — Merge first. Pure Foundation, no UI dependencies. All IC-1 wire types defined here; T-2.2 and T-2.3 code may eventually import from this layer.
+
+2. **`feat/p2-t2-3-terminal`** — Merge second. Contains both T-2.2 (Auth) and T-2.3 (Terminal) implementations. Depends on nothing from T-2.2's (empty) branch.
+
+3. **`feat/p2-t2-2-pairing`** — Merge last (or close without merge). The branch is empty and the implementation already landed via T-2.3. If the pairing agent re-uses the branch to deliver a QR-scanning integration test or additional pairing UI, it can be rebased on top of T-2.3's merge.
+
+4. **`feat/p2-tests`** (this branch) — Can merge any time after T-2.1; the tests import `piRemote` which will contain all source files after the three implementation branches are merged.
+
+---
+
+## Test Files Created
+
+| File | Tests | Coverage |
+|------|-------|----------|
+| `FrameCodecTests.swift` | 21 | BinaryFrame.decode, ClientToServer encoding (all 5 cases), ServerToClient decoding (all 4 types), round-trip |
+| `ResumeCursorTests.swift` | 11 | Save/load, update overwrites, zero seq, UInt64.max, clear, session isolation |
+| `PairingTests.swift` | 15 | Valid URLs, missing params (3 cases), wrong scheme (2), empty/missing port, error type assertions |
+| `KeychainTests.swift` | 7 | Round-trip, upsert, missing→notFound, delete clears, delete no-op, production key not touched, generic Codable |
+| `ThemeTests.swift` | 18 | ansiColors count, color range, dark≠github, id values, background values, SwiftTerm conversion, ThemeStore select, Codable round-trip |
+
+**Total: 72 unit tests across 5 files.**
diff --git a/Tests/CoreTests/ResumeCursorTests.swift b/Tests/CoreTests/ResumeCursorTests.swift
new file mode 100644
index 0000000..bb4ec5b
--- /dev/null
+++ b/Tests/CoreTests/ResumeCursorTests.swift
@@ -0,0 +1,136 @@
+// ResumeCursorTests.swift
+// Unit tests for ResumeCursor — persistence of IC-1 sequence numbers.
+//
+// Uses a named UserDefaults suite per test to stay completely isolated from
+// the real app defaults and from other test cases.
+
+import XCTest
+@testable import piRemote
+
+final class ResumeCursorTests: XCTestCase {
+
+    // Each test creates its own defaults suite; tearDown removes it.
+    private var suiteName: String!
+    private var defaults:  UserDefaults!
+    private var cursor:    ResumeCursor!
+
+    override func setUp() {
+        super.setUp()
+        suiteName = "ResumeCursorTests.\(UUID().uuidString)"
+        defaults  = UserDefaults(suiteName: suiteName)!
+        cursor    = ResumeCursor(defaults: defaults)
+    }
+
+    override func tearDown() {
+        defaults.removePersistentDomain(forName: suiteName)
+        super.tearDown()
+    }
+
+    // =========================================================================
+    // MARK: 1. Initial state
+    // =========================================================================
+
+    func testLastSeq_freshSession_returnsNil() {
+        XCTAssertNil(cursor.lastSeq(for: "session-A"),
+                     "No stored cursor → must return nil")
+    }
+
+    // =========================================================================
+    // MARK: 2. Save + load
+    // =========================================================================
+
+    func testUpdateAndLoad_returnsStoredValue() {
+        cursor.update(sessionId: "s1", seq: 42)
+        XCTAssertEqual(cursor.lastSeq(for: "s1"), 42)
+    }
+
+    func testUpdate_overwrites_previousValue() {
+        cursor.update(sessionId: "s1", seq: 1)
+        cursor.update(sessionId: "s1", seq: 999)
+        XCTAssertEqual(cursor.lastSeq(for: "s1"), 999,
+                       "Second update must overwrite the first")
+    }
+
+    func testUpdate_zeroSeq_isStoredAndDistinctFromMissing() {
+        // Before update: nil
+        XCTAssertNil(cursor.lastSeq(for: "s-zero"))
+        // After update with 0: 0 (not nil)
+        cursor.update(sessionId: "s-zero", seq: 0)
+        XCTAssertEqual(cursor.lastSeq(for: "s-zero"), 0)
+    }
+
+    // =========================================================================
+    // MARK: 3. UInt64 boundary values
+    // =========================================================================
+
+    func testUpdate_maxUInt64_roundTrips() {
+        cursor.update(sessionId: "s-max", seq: UInt64.max)
+        XCTAssertEqual(cursor.lastSeq(for: "s-max"), UInt64.max,
+                       "UInt64.max must survive the Int64-bit-pattern round-trip")
+    }
+
+    func testUpdate_largeValue_roundTrips() {
+        let large: UInt64 = 1_000_000_000_000
+        cursor.update(sessionId: "s-large", seq: large)
+        XCTAssertEqual(cursor.lastSeq(for: "s-large"), large)
+    }
+
+    // =========================================================================
+    // MARK: 4. Clear
+    // =========================================================================
+
+    func testClear_removesEntry() {
+        cursor.update(sessionId: "s1", seq: 100)
+        cursor.clear(sessionId: "s1")
+        XCTAssertNil(cursor.lastSeq(for: "s1"),
+                     "After clear, lastSeq must return nil")
+    }
+
+    func testClear_missingEntry_isNoOp() {
+        // Clearing a key that was never written must not throw or crash.
+        cursor.clear(sessionId: "never-written")
+        XCTAssertNil(cursor.lastSeq(for: "never-written"))
+    }
+
+    // =========================================================================
+    // MARK: 5. Session isolation
+    // =========================================================================
+
+    func testIndependentSessions_doNotInterfere() {
+        cursor.update(sessionId: "alpha", seq: 10)
+        cursor.update(sessionId: "beta",  seq: 20)
+
+        XCTAssertEqual(cursor.lastSeq(for: "alpha"), 10)
+        XCTAssertEqual(cursor.lastSeq(for: "beta"),  20)
+    }
+
+    func testClearOneSession_doesNotAffectOther() {
+        cursor.update(sessionId: "alpha", seq: 10)
+        cursor.update(sessionId: "beta",  seq: 20)
+
+        cursor.clear(sessionId: "alpha")
+
+        XCTAssertNil(cursor.lastSeq(for: "alpha"),
+                     "alpha should be nil after clear")
+        XCTAssertEqual(cursor.lastSeq(for: "beta"), 20,
+                       "beta must be unaffected by clearing alpha")
+    }
+
+    func testThreeIndependentSessions() {
+        let ids: [String] = ["s1", "s2", "s3"]
+        let seqs: [UInt64] = [1, 2, 3]
+        zip(ids, seqs).forEach { cursor.update(sessionId: $0, seq: $1) }
+        zip(ids, seqs).forEach {
+            XCTAssertEqual(cursor.lastSeq(for: $0), $1)
+        }
+    }
+
+    // =========================================================================
+    // MARK: 6. Missing entry (never stored)
+    // =========================================================================
+
+    func testMissingEntry_returnsNil() {
+        // Confirm nil for a key that was never written.
+        XCTAssertNil(cursor.lastSeq(for: "completely-absent"))
+    }
+}
diff --git a/Tests/CoreTests/ThemeTests.swift b/Tests/CoreTests/ThemeTests.swift
new file mode 100644
index 0000000..db590c5
--- /dev/null
+++ b/Tests/CoreTests/ThemeTests.swift
@@ -0,0 +1,169 @@
+// ThemeTests.swift
+// Unit tests for TerminalTheme, ThemeColor, ThemeStore, and FontStore.
+//
+// These tests exercise built-in theme validity and store selection logic.
+// No UIKit rendering or simulator is required for the pure-struct tests;
+// ThemeStore / FontStore tests require @MainActor and a run loop.
+
+import XCTest
+@testable import piRemote
+
+final class ThemeTests: XCTestCase {
+
+    // =========================================================================
+    // MARK: 1. TerminalTheme — built-in theme invariants
+    // =========================================================================
+
+    func testDark_hasExactly16AnsiColors() {
+        XCTAssertEqual(TerminalTheme.dark.ansiColors.count, 16,
+                       ".dark must have exactly 16 ANSI color entries")
+    }
+
+    func testGitHub_hasExactly16AnsiColors() {
+        XCTAssertEqual(TerminalTheme.github.ansiColors.count, 16,
+                       ".github must have exactly 16 ANSI color entries")
+    }
+
+    // =========================================================================
+    // MARK: 2. ThemeColor values are in the 0–255 range
+    // =========================================================================
+    // ThemeColor stores UInt8 components, so they are structurally bounded to
+    // 0–255.  These tests make the contract explicit and guard against future
+    // refactors that might widen the type.
+
+    func testDark_allAnsiColorComponents_inRange() {
+        for (index, color) in TerminalTheme.dark.ansiColors.enumerated() {
+            assertColorInRange(color, label: "dark[\(index)]")
+        }
+        assertColorInRange(TerminalTheme.dark.foreground, label: "dark.foreground")
+        assertColorInRange(TerminalTheme.dark.background, label: "dark.background")
+        assertColorInRange(TerminalTheme.dark.cursor,     label: "dark.cursor")
+    }
+
+    func testGitHub_allAnsiColorComponents_inRange() {
+        for (index, color) in TerminalTheme.github.ansiColors.enumerated() {
+            assertColorInRange(color, label: "github[\(index)]")
+        }
+        assertColorInRange(TerminalTheme.github.foreground, label: "github.foreground")
+        assertColorInRange(TerminalTheme.github.background, label: "github.background")
+        assertColorInRange(TerminalTheme.github.cursor,     label: "github.cursor")
+    }
+
+    private func assertColorInRange(_ color: ThemeColor, label: String) {
+        // UInt8 is intrinsically 0–255; the assertions below make the expectation readable.
+        XCTAssertLessThanOrEqual(color.r, 255, "\(label).r out of range")
+        XCTAssertLessThanOrEqual(color.g, 255, "\(label).g out of range")
+        XCTAssertLessThanOrEqual(color.b, 255, "\(label).b out of range")
+    }
+
+    // =========================================================================
+    // MARK: 3. .dark and .github are distinct themes
+    // =========================================================================
+
+    func testDarkAndGitHub_haveDistinctIds() {
+        XCTAssertNotEqual(TerminalTheme.dark.id, TerminalTheme.github.id,
+                          "Built-in themes must have unique IDs")
+    }
+
+    func testDarkAndGitHub_haveDistinctBackgrounds() {
+        // "Dark (Hacker)" has a pure-black background; GitHub Dark does not.
+        XCTAssertNotEqual(TerminalTheme.dark.background, TerminalTheme.github.background,
+                          "Background colors must differ between dark and github themes")
+    }
+
+    func testDarkAndGitHub_areNotEqual() {
+        XCTAssertNotEqual(TerminalTheme.dark, TerminalTheme.github,
+                          ".dark and .github must be distinct themes")
+    }
+
+    // =========================================================================
+    // MARK: 4. TerminalTheme identities
+    // =========================================================================
+
+    func testDark_hasExpectedId() {
+        XCTAssertEqual(TerminalTheme.dark.id, "dark")
+    }
+
+    func testGitHub_hasExpectedId() {
+        XCTAssertEqual(TerminalTheme.github.id, "github")
+    }
+
+    func testDark_backgroundIsBlack() {
+        let bg = TerminalTheme.dark.background
+        XCTAssertEqual(bg.r, 0x00, "Dark background R must be 0x00")
+        XCTAssertEqual(bg.g, 0x00, "Dark background G must be 0x00")
+        XCTAssertEqual(bg.b, 0x00, "Dark background B must be 0x00")
+    }
+
+    func testGitHub_backgroundMatchesSpec() {
+        // GitHub Dark background: #0d1117
+        let bg = TerminalTheme.github.background
+        XCTAssertEqual(bg.r, 0x0D, "GitHub background R must be 0x0D")
+        XCTAssertEqual(bg.g, 0x11, "GitHub background G must be 0x11")
+        XCTAssertEqual(bg.b, 0x17, "GitHub background B must be 0x17")
+    }
+
+    // =========================================================================
+    // MARK: 5. TerminalTheme.toSwiftTermColor conversion
+    // =========================================================================
+
+    func testToSwiftTermColor_white_mapsTo65535() {
+        // 255 × 257 = 65535 (= UInt16.max)
+        let white  = ThemeColor(r: 255, g: 255, b: 255)
+        let stColor = TerminalTheme.dark.toSwiftTermColor(white)
+        XCTAssertEqual(stColor.red,   65535)
+        XCTAssertEqual(stColor.green, 65535)
+        XCTAssertEqual(stColor.blue,  65535)
+    }
+
+    func testToSwiftTermColor_black_mapsToZero() {
+        let black   = ThemeColor(r: 0, g: 0, b: 0)
+        let stColor = TerminalTheme.dark.toSwiftTermColor(black)
+        XCTAssertEqual(stColor.red,   0)
+        XCTAssertEqual(stColor.green, 0)
+        XCTAssertEqual(stColor.blue,  0)
+    }
+
+    func testSwiftTermAnsiColors_has16Entries() {
+        XCTAssertEqual(TerminalTheme.dark.swiftTermAnsiColors.count,   16)
+        XCTAssertEqual(TerminalTheme.github.swiftTermAnsiColors.count, 16)
+    }
+
+    // =========================================================================
+    // MARK: 6. ThemeStore — selection and persistence
+    // =========================================================================
+
+    @MainActor
+    func testThemeStore_available_containsBothBuiltins() {
+        let store = ThemeStore.shared
+        let ids   = store.available.map(\.id)
+        XCTAssertTrue(ids.contains("dark"),   "Available themes must include 'dark'")
+        XCTAssertTrue(ids.contains("github"), "Available themes must include 'github'")
+    }
+
+    @MainActor
+    func testThemeStore_select_updatesCurrent() {
+        let store  = ThemeStore.shared
+        let before = store.current
+
+        // Select whichever theme is NOT currently active.
+        let next = store.available.first(where: { $0.id != before.id })!
+        store.select(next)
+        XCTAssertEqual(store.current.id, next.id,
+                       "select(_:) must update current immediately")
+
+        // Restore original selection so we don't bleed state into other tests.
+        store.select(before)
+    }
+
+    // =========================================================================
+    // MARK: 7. TerminalTheme Codable round-trip
+    // =========================================================================
+
+    func testTerminalTheme_codable_roundTrips() throws {
+        let theme  = TerminalTheme.dark
+        let data   = try JSONEncoder().encode(theme)
+        let loaded = try JSONDecoder().decode(TerminalTheme.self, from: data)
+        XCTAssertEqual(loaded, theme, "TerminalTheme must survive a JSON round-trip")
+    }
+}