feat: scaffold Fish Audio speech provider plugin

- index.ts: plugin entry with definePluginEntry + registerSpeechProvider
- speech-provider.ts: full SpeechProviderPlugin implementation
  - resolveConfig from messages.tts.providers.fish-audio
  - parseDirectiveToken for voice, model, speed, latency, temperature, top_p
  - listVoices merging official + user's own voices
  - synthesize with format-aware output (opus for voice-note, mp3 otherwise)
  - stub Talk Mode (resolveTalkConfig/resolveTalkOverrides)
- tts.ts: raw fishAudioTTS() fetch + listFishAudioVoices()
  - streaming chunked → buffer, error body included in exceptions
  - parallel voice listing with graceful partial failure
- speech-provider.test.ts: voice ID validation tests
- openclaw.plugin.json: speechProviders contract
- package.json: peer dep on openclaw >=2026.3.0

package.json

@@ -0,0 +1,21 @@
+{
+  "name": "@openclaw/fish-audio-speech",
+  "version": "0.1.0",
+  "description": "Fish Audio TTS speech provider plugin for OpenClaw",
+  "type": "module",
+  "license": "MIT",
+  "openclaw": {
+    "extensions": [
+      "./index.ts"
+    ]
+  },
+  "peerDependencies": {
+    "openclaw": ">=2026.3.0"
+  },
+  "devDependencies": {
+    "vitest": "^3.0.0"
+  },
+  "scripts": {
+    "test": "vitest run"
+  }
+}