feat(voice): backend voice picker + advanced controls behind disclosure (#742) (#743)

* feat(voice): voice personality, picker catalog, and prompt layer foundation

- voicePickerCatalog.ts: per-backend voice lists for Gemini and Qwen with
  resolve helpers (resolveGeminiLiveVoice, resolveQwenRealtimeVoice)
- voicePersonality.ts: VoicePersonalityPreferences schema, presets, composed
  system prompt with identity/character/response-length layers
- voicePromptLayers.ts: buildResolvedVoiceSystemPrompt, preset delivery snippets
- voiceSystemPromptParam.ts: hub-side base64url decode for ?systemPrompt=
- voicePickerPreferences.ts, voicePersonalitySession.ts: browser-side encode,
  decode, and storage helpers
- useVoicePersonality: React hook for preferences persistence

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* fix(voice): preset delivery included when non-balanced preset selected; restore test typecheck

- isDefaultVoicePersonality: add preset check so warm/calm/direct presets
  trigger the delivery snippet instead of being treated as default
- web/tsconfig.json: remove test file exclusion from typecheck (restoring
  strict coverage of test code); fix resulting type error in mock declaration

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* fix(voice): include use_speaker_boost in ElevenLabs TTS override payload

The checkbox persisted the pref but ttsDiffersFromDefault and
buildElevenLabsTtsOverride both omitted it, so the setting was never
sent to the agent.

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* test(voice): update speaker_boost test to assert it IS included in override

The previous test asserted use_speaker_boost was omitted; now it's
correctly included in the TTS payload.

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* fix(voice): authorize use_speaker_boost in ElevenLabs override schema

Add use_speaker_boost to both the VoiceAgentConfig tts override type
and the buildVoiceAgentConfig() platform_settings so the field is
accepted by the ElevenLabs agent runtime.

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* fix(voice): propagate full language code through composed prompt, not just zh

getDefaultVoiceSystemPrompt and resolveComposedVoiceSystemPrompt were
filtering language to zh-only before passing to composeVoiceAgentPrompt.
Now append buildVoiceLanguageBlock(language) after composition so French,
Spanish, Japanese etc. reach Gemini/Qwen sessions correctly.

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* fix(voice): only append language block when language explicitly set

Building language block unconditionally when no language is given
caused getDefaultVoiceSystemPrompt() to diverge from VOICE_SYSTEM_PROMPT.
Only append the block when a code is explicitly provided.

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

* fix(voice): always include language block for Gemini/Qwen in composed prompt

When auto-detect is on (language=undefined), the composed prompt sent
via hub proxy was losing the language auto-detect instruction because
the block was only added when language was explicitly set.

Now: ElevenLabs skips the block (has its own language field); Gemini/Qwen
always include it — undefined produces the auto-detect block, an explicit
code produces the appropriate language instruction.

via [HAPI](https://hapi.run)

Co-Authored-By: HAPI <noreply@hapi.run>

---------

Co-authored-by: HAPI <noreply@hapi.run>

shared/src/voice.gemini.test.ts

@@ -1,5 +1,13 @@
 import { describe, expect, test } from 'bun:test'
-import { buildGeminiLiveSetupMessage, buildQwenSessionUpdateMessage, isQwenSafeClientFrame, GEMINI_LIVE_MODEL, GEMINI_LIVE_VOICE, QWEN_REALTIME_VOICE } from './voice'
+import {
+    buildGeminiLiveSetupMessage,
+    buildQwenSessionUpdateMessage,
+    isQwenSafeClientFrame,
+    GEMINI_LIVE_MODEL,
+    GEMINI_LIVE_VOICE,
+    QWEN_REALTIME_VOICE
+} from './voice'
+import { resolveGeminiLiveVoice, resolveQwenRealtimeVoice } from './voicePickerCatalog'
 
 describe('buildGeminiLiveSetupMessage', () => {
     test('locks model and voice to HAPI defaults', () => {
@@ -18,15 +26,50 @@ describe('buildGeminiLiveSetupMessage', () => {
         const zhText = (zh.setup.systemInstruction as { parts: Array<{ text: string }> }).parts[0].text
         expect(zhText.length).toBeGreaterThan(enText.length)
     })
+
+    test('uses selected prebuilt voice when valid', () => {
+        const msg = buildGeminiLiveSetupMessage(undefined, 'Puck')
+        const speech = msg.setup.generationConfig as {
+            speechConfig?: { voiceConfig?: { prebuiltVoiceConfig?: { voiceName?: string } } }
+        }
+        expect(speech.speechConfig?.voiceConfig?.prebuiltVoiceConfig?.voiceName).toBe('Puck')
+    })
+
+    test('honors custom system instruction override', () => {
+        const custom = 'Speak only in haiku.'
+        const msg = buildGeminiLiveSetupMessage(undefined, undefined, custom)
+        const text = (msg.setup.systemInstruction as { parts: Array<{ text: string }> }).parts[0].text
+        expect(text).toBe(custom)
+    })
+
+    test('falls back to default for unknown voice names', () => {
+        const msg = buildGeminiLiveSetupMessage(undefined, 'NotARealVoice')
+        const speech = msg.setup.generationConfig as {
+            speechConfig?: { voiceConfig?: { prebuiltVoiceConfig?: { voiceName?: string } } }
+        }
+        expect(speech.speechConfig?.voiceConfig?.prebuiltVoiceConfig?.voiceName).toBe(resolveGeminiLiveVoice())
+    })
 })
 
 describe('buildQwenSessionUpdateMessage', () => {
-    test('locks voice to HAPI default', () => {
+    test('locks voice to HAPI default when no voice name supplied', () => {
         const msg = buildQwenSessionUpdateMessage()
         const session = msg.session as { voice: string }
         expect(session.voice).toBe(QWEN_REALTIME_VOICE)
     })
 
+    test('uses selected prebuilt voice when valid', () => {
+        const msg = buildQwenSessionUpdateMessage(undefined, 'Ethan')
+        const session = msg.session as { voice: string }
+        expect(session.voice).toBe('Ethan')
+    })
+
+    test('falls back to catalog default for unknown voice names', () => {
+        const msg = buildQwenSessionUpdateMessage(undefined, 'NotARealVoice')
+        const session = msg.session as { voice: string }
+        expect(session.voice).toBe(resolveQwenRealtimeVoice())
+    })
+
     test('includes both tools', () => {
         const msg = buildQwenSessionUpdateMessage()
         // Realtime shape: flat {type, name, description, parameters} — NOT chat-completions {function:{...}}