feat(speech): add prompt voice input (#249)

## Summary
- add server-backed speech capabilities and transcription endpoints plus
UI settings for speech configuration
- add push-to-talk prompt voice input with microphone controls,
transcription insertion, and browser capability gating
- keep prompt controls aligned by restoring right-side nav placement and
moving the mic beside the expand control

packages/opencode-config/package.json

@@ -4,6 +4,6 @@
   "private": true,
   "license": "MIT",
   "dependencies": {
-    "@opencode-ai/plugin": "1.2.24"
+    "@opencode-ai/plugin": "1.2.14"
   }
 }