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+).

.github/workflows/ci.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Install XcodeGen
         run: brew install xcodegen
       - name: Generate project
-        run: xcodegen generate
+        run: ./Scripts/generate-xcodeproj.sh
       - name: Build
         run: |
           set -o pipefail
@@ -76,7 +76,7 @@ jobs:
       - name: Install XcodeGen
         run: brew install xcodegen
       - name: Generate project
-        run: xcodegen generate
+        run: ./Scripts/generate-xcodeproj.sh
       - name: Run tests
         run: |
           set -o pipefail