perf(asr): speed up local Flow dictation and land CLM/keyboard refactor

Reduce perceived latency from key release to final text:
- Adaptive chunking: 2.5s first chunk + 5s follow-ups so short
  utterances start on-device recognition while still recording.
- Session-level ASR warmup and audio-format cache reuse to remove
  per-utterance cold-start of SpeechAnalyzer.
- Mirror live pipelined partials to the keyboard transcript line via
  a new flow.transcriptionPartial App Group key + Darwin ping.

Also commits the accumulated custom language model, Flow session,
keyboard extension restructure, and Xiaomi MiMo provider work in
progress on this branch.

OSGKeyboardShared/Models/PersonalDictionary.swift

@@ -108,7 +108,9 @@ extension PersonalDictionary.Entry {
     /// learner. Users can re-classify later from Settings.
     public static func inferCategory(for term: String) -> Category {
         let hasUpper = term.contains(where: { $0.isUppercase })
-        let hasDigit = term.contains(where: { $0.isNumber })
+        let hasDigit = term.unicodeScalars.contains { scalar in
+            CharacterSet.decimalDigits.contains(scalar) && scalar.isASCII
+        }
         let hasLatin = term.unicodeScalars.contains { scalar in
             CharacterSet.letters.contains(scalar) && scalar.isASCII
         }