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 +1,69 @@
+// FlowUtteranceChunkConfig.swift
+// OSGKeyboard · Shared
+//
+// Chunking policy for pipelined Flow utterance ASR (up to 3 minutes).
+
+import Foundation
+
+public struct FlowUtteranceChunkConfig: Sendable, Equatable {
+    /// Target maximum duration per ASR chunk.
+    public let maxChunkDurationSeconds: TimeInterval
+    /// Tail overlap fed into the next chunk for boundary dedup when stitching.
+    public let overlapDurationSeconds: TimeInterval
+    /// After hitting the max window, wait up to this long for a pause before hard-splitting.
+    public let pauseExtensionMaxSeconds: TimeInterval
+    /// RMS below this is treated as a pause candidate (Float32 mono @ 16 kHz).
+    public let pauseRMSThreshold: Float
+    public let sampleRate: Int
+
+    public init(
+        maxChunkDurationSeconds: TimeInterval,
+        overlapDurationSeconds: TimeInterval,
+        pauseExtensionMaxSeconds: TimeInterval,
+        pauseRMSThreshold: Float,
+        sampleRate: Int
+    ) {
+        self.maxChunkDurationSeconds = maxChunkDurationSeconds
+        self.overlapDurationSeconds = overlapDurationSeconds
+        self.pauseExtensionMaxSeconds = pauseExtensionMaxSeconds
+        self.pauseRMSThreshold = pauseRMSThreshold
+        self.sampleRate = sampleRate
+    }
+
+    public var maxChunkSamples: Int {
+        Int(maxChunkDurationSeconds * Double(sampleRate))
+    }
+
+    public var overlapSamples: Int {
+        Int(overlapDurationSeconds * Double(sampleRate))
+    }
+
+    public var pauseExtensionSamples: Int {
+        Int(pauseExtensionMaxSeconds * Double(sampleRate))
+    }
+
+    /// Default for keyboard Flow utterances (≤ 3 min, pipelined ASR).
+    public static let flowDefault = FlowUtteranceChunkConfig(
+        maxChunkDurationSeconds: 30,
+        overlapDurationSeconds: 0.5,
+        pauseExtensionMaxSeconds: 2,
+        pauseRMSThreshold: 0.015,
+        sampleRate: 16_000
+    )
+}
+
+public struct UtteranceAudioChunk: Sendable, Equatable {
+    public let index: Int
+    public let samples: [Float]
+    public let isLast: Bool
+
+    public init(index: Int, samples: [Float], isLast: Bool) {
+        self.index = index
+        self.samples = samples
+        self.isLast = isLast
+    }
+
+    public var durationSeconds: Double {
+        Double(samples.count) / 16_000.0
+    }
+}