feat: migrate on-device Qwen3 ASR to CoreML for background Flow dictation

Replace MLX GPU inference with CoreML bundles so transcription continues while the host app is backgrounded. Adds model download and warm-up, vendored Qwen3Speech, and updates onboarding, settings, and copy for the ~1.6 GB CoreML package (iOS 18+).
2026-06-23 00:46:58 +08:00
parent 5e5122f172
commit df1c5ff32c
160 changed files with 22080 additions and 492 deletions
@@ -0,0 +1,56 @@
+// LocalASRBackend.swift
+// OSGKeyboard · Shared
+//
+// Identifies which on-device speech recognition engine to use when the
+// user picks the "local" engine (no cloud LLM polish). The shared
+// factory `ASRServiceFactory` dispatches on this enum; the settings UI
+// renders it as a picker.
+//
+// Why an enum in `Shared` rather than living next to the concrete
+// `ASRService` implementations: the value must be serialisable into
+// the App Group store (so the keyboard extension can observe the
+// selection), exposed via `ProviderConfig` (UI binding) and consumed
+// by every layer that asks for an ASR backend.
+
+import Foundation
+
+public enum LocalASRBackend: String, CaseIterable, Identifiable, Sendable, Codable {
+    /// iOS 26 `SpeechAnalyzer` + `DictationTranscriber`. Always
+    /// on-device, no asset download, ships with iOS. Default for every
+    /// fresh install — anything else is opt-in.
+    case speechAnalyzer
+
+    /// Qwen3-ASR-0.6B via CoreML (Neural Engine + CPU). Stronger on Chinese
+    /// dialects and noisy audio than `SpeechAnalyzer`, works in Flow while
+    /// the host app is backgrounded, but requires a ~1.6 GB download on first
+    /// use and iOS 18+.
+    case qwen3ASR
+
+    public var id: String { rawValue }
+
+    /// Localisation key for the human label in the settings picker.
+    public var labelKey: String {
+        switch self {
+        case .speechAnalyzer: return "asr.backend.speechAnalyzer.label"
+        case .qwen3ASR:        return "asr.backend.qwen3.label"
+        }
+    }
+
+    /// Localisation key for the one-line subtitle shown under the label.
+    public var blurbKey: String {
+        switch self {
+        case .speechAnalyzer: return "asr.backend.speechAnalyzer.blurb"
+        case .qwen3ASR:        return "asr.backend.qwen3.blurb"
+        }
+    }
+
+    /// Whether this backend needs the user to download a model file
+    /// before it can run. Used to gate the "Downloading Qwen3-ASR" UI
+    /// in a follow-up; for now we just expose the flag.
+    public var requiresModelDownload: Bool {
+        switch self {
+        case .speechAnalyzer: return false
+        case .qwen3ASR:        return true
+        }
+    }
+}