feat: comprehensive rewrite — push-to-talk pipeline, Typeless UI, Chinese

This is a major rewrite of OpenLessKeyboard, renamed to OSGKeyboard
and rebuilt end-to-end. 59 files changed (+3205/-1550).

Architecture
------------
- Rename project, targets, directories from OpenLess* to OSGKeyboard*
  (OpenLess / OpenLessKeyboard / OpenLessShared / OpenLessTests).
- AudioCaptureService rewritten as @unchecked Sendable class with
  OSAllocatedUnfairLock instead of an actor, so it survives Swift 6
  strict-concurrency checks while still serialising engine + converter
  state correctly.
- Single design system (Palette / Spacing / Radius / TypeStyle /
  Motion) lifted into OSGKeyboardShared so the host app and the
  keyboard extension stay in lock-step.

Push-to-talk — first-principles fix
-----------------------------------
- App Group + audio-input entitlements were stripped by Xcode's
  Automatic Signing. They are now declared in project.yml so
  'xcodegen generate' re-emits them every time. iOS Developer
  Account is untouched; only the App Group capability was added.
- State machine uses a real stored `phase` (was a derived shim
  that locked out every press after the first because
  recordStream was never nilled after the pipeline finished).
- Microphone permission is requested inside pressBegan (async
  Task) so the press flow optimistically enters .recording;
  permission denial surfaces a short error and returns to idle.
- Replaced LongPressGesture(0.15s) with a DragGesture +
  TapGesture pair separated by pressArmed, so a single tap no
  longer fires both onPressBegan and onTap simultaneously.
- Real RMS / peak level meter from the AVAudioEngine tap (was a
  pseudo-random walk); the visible waveform is now driven by
  actual audio.
- SFSpeechRecognizer(locale:) with selectable ASR locales
  (auto / zh-Hans / zh-Hant / en-US / ja-JP / ko-KR) for
  first-class Chinese / English / Japanese / Korean dictation,
  with on-device recognition when supported.
- AVAudioSession now deactivates on stop so other apps' audio
  routing is restored.

Keyboard UI — Typeless-inspired layout
---------------------------------------
- Hero area is 280 pt with a 96 pt record disc, breathing outer
  ring, and a 12-bar waveform driven by the real RMS.
- inputView.allowsSelfSizing + a heightAnchor constraint so iOS
  no longer crops the keyboard under the Spotlight bar / home
  indicator.
- Top bar: mode chip (Off / 转写 / 润色) + locale chip
  (Auto / 简体 / 繁體 / EN / 日 / 한) + status badge + ⚙.
- Bottom bar: globe / delete / 空格 / return — all 40 pt and
  balanced.
- RecordButton onPressEnded is now safe to fire from a quick
  press; pressArmed prevents double-firing.

LLM / Polishing
---------------
- LLMClient: stopped leaking the server response body in errors
  (server body is now logged at debug, never surfaced to UI);
  added a dedicated .rateLimited case for 429.
- PolishingService timeout 8s → 12s to accommodate slower
  domestic LLM providers.
- AppGroupStore.defaultSystemPrompt is now provider-aware
  (Chinese for zhipu/moonshot/qwen/deepseek, English otherwise).

Onboarding & Settings
---------------------
- Re-themed OnboardingView / HomeView / SettingsView on the
  new design system.
- ProviderPickerSection now shows 6 providers (OpenAI, DeepSeek,
  Qwen DashScope, 智谱 GLM, 月之暗面 Moonshot, Custom) with
  blurb + selected accent.
- PickerRow for Mode and ASR locale; System Prompt editor with
  reset-to-default.
- API settings page "Get an API key" used SwiftUI Link, which
  has a hit-test bug on iOS 18 that ate gestures from adjacent
  TextFields (manifested as "typing jumps to a website"). It is
  now an explicit Button + contentShape + .submitLabel(.done) on
  the fields.

Polish & tests
--------------
- LLMClientTests: 4 unit tests passing (ProviderConfig
  persistence + OpenAI request/response + HTTP error + missing
  key); test App Group renamed to the correct identifier.
- ProviderConfig.apply now captures the previous provider id
  *before* mutating, so switching providers actually resets the
  system prompt to the new default.

Build
-----
- Swift 6 strict concurrency, iOS 18.0 deployment target.
- Tested on Xcode 26 + iPhone 17 Pro simulator. A real device on
  iOS 27 beta aborts with __abort_with_payload (dispatch
  library ABI mismatch); use an iOS 18 real device or the
  iOS 26 simulator for now.

🤖 Generated with Claude Code

OSGKeyboardTests/LLMClientTests.swift

@@ -0,0 +1,132 @@
+// LLMClientTests.swift
+// OSGKeyboard · Tests
+//
+// Unit tests for the OpenAI-compatible LLM client using URLProtocol stub.
+
+import XCTest
+@testable import OSGKeyboard
+@testable import OSGKeyboardShared
+
+final class LLMClientTests: XCTestCase {
+
+    // MARK: - ProviderConfig persistence
+
+    func testProviderConfigPersistsAcrossInstances() {
+        let suiteName = "group.com.osgkeyboard.shared.tests"
+        let defaults = UserDefaults(suiteName: suiteName)!
+        defaults.removePersistentDomain(forName: suiteName)
+
+        let config1 = ProviderConfig(defaults: defaults)
+        config1.baseURL = "https://example.com/v1"
+        config1.apiKey = "test-key"
+        config1.model = "test-model"
+
+        let config2 = ProviderConfig(defaults: defaults)
+        XCTAssertEqual(config2.baseURL, "https://example.com/v1")
+        XCTAssertEqual(config2.apiKey, "test-key")
+        XCTAssertEqual(config2.model, "test-model")
+        XCTAssertTrue(config2.isConfigured)
+    }
+
+    // MARK: - OpenAICompatibleClient
+
+    func testPolishSendsCorrectRequestAndDecodesResponse() async throws {
+        StubURLProtocolStorage.config = (200, """
+        {
+          "id": "chatcmpl-1",
+          "choices": [
+            { "index": 0, "message": { "role": "assistant", "content": "Hello, world!" }, "finish_reason": "stop" }
+          ]
+        }
+        """.data(using: .utf8)!)
+        defer { StubURLProtocolStorage.config = nil }
+
+        let cfg = URLSessionConfiguration.ephemeral
+        cfg.protocolClasses = [StubURLProtocol.self]
+        let session = URLSession(configuration: cfg)
+
+        let client = OpenAICompatibleClient(
+            baseURL: "https://example.com/v1",
+            apiKey: "sk-test",
+            model: "test-model",
+            session: session
+        )
+
+        let result = try await client.polish("hi", systemPrompt: "be brief")
+        XCTAssertEqual(result, "Hello, world!")
+        let req = StubURLProtocolStorage.lastRequest
+        XCTAssertEqual(req?.httpMethod, "POST")
+        XCTAssertTrue(req?.value(forHTTPHeaderField: "Authorization")?.hasPrefix("Bearer ") == true)
+    }
+
+    func testPolishThrowsOnHTTPError() async {
+        StubURLProtocolStorage.config = (401, "Unauthorized".data(using: .utf8)!)
+        defer { StubURLProtocolStorage.config = nil }
+
+        let cfg = URLSessionConfiguration.ephemeral
+        cfg.protocolClasses = [StubURLProtocol.self]
+        let session = URLSession(configuration: cfg)
+
+        let client = OpenAICompatibleClient(
+            baseURL: "https://example.com/v1",
+            apiKey: "sk-test",
+            model: "m",
+            session: session
+        )
+
+        do {
+            _ = try await client.polish("hi", systemPrompt: "p")
+            XCTFail("expected error")
+        } catch let LLMError.http(status, _) {
+            XCTAssertEqual(status, 401)
+        } catch {
+            XCTFail("wrong error: \(error)")
+        }
+    }
+
+    func testPolishThrowsWhenAPIKeyMissing() async {
+        let client = OpenAICompatibleClient(
+            baseURL: "https://example.com/v1",
+            apiKey: "",
+            model: "m"
+        )
+        do {
+            _ = try await client.polish("hi", systemPrompt: "p")
+            XCTFail("expected error")
+        } catch LLMError.noAPIKey {
+            // ok
+        } catch {
+            XCTFail("wrong error: \(error)")
+        }
+    }
+}
+
+// MARK: - URLProtocol stub
+
+/// Per-test stub config holder. Tests set these via `StubURLProtocol.config =`
+/// before invoking the code under test, then reset to nil in cleanup.
+private enum StubURLProtocolStorage {
+    nonisolated(unsafe) static var config: (statusCode: Int, body: Data)?
+    nonisolated(unsafe) static var lastRequest: URLRequest?
+}
+
+private final class StubURLProtocol: URLProtocol, @unchecked Sendable {
+    override class func canInit(with request: URLRequest) -> Bool { true }
+    override class func canonicalRequest(for request: URLRequest) -> URLRequest { request }
+
+    override func startLoading() {
+        let cfg = StubURLProtocolStorage.config ?? (statusCode: 200, body: Data())
+        StubURLProtocolStorage.lastRequest = request
+        let response = HTTPURLResponse(
+            url: request.url!,
+            statusCode: cfg.statusCode,
+            httpVersion: "HTTP/1.1",
+            headerFields: ["Content-Type": "application/json"]
+        )!
+        client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: .notAllowed)
+        client?.urlProtocol(self, didLoad: cfg.body)
+        client?.urlProtocolDidFinishLoading(self)
+    }
+
+    override func stopLoading() {}
+}