feat(web): PillNav bar mode, fullscreen, local STT + mic button

PillNav overhaul:
- Dropdown-as-bar: theme/AI/sync/user menus render as horizontal
  bars in the bottom stack (PillDropdownBar) instead of floating
  popovers. New onOpenBar/activeBarId props on PillNavigation.
- iconOnly pills: tags/search/workbench-tabs pills show only icons.
  Home pill removed. New iconOnly flag on PillNavItem.
- Segmented toggle groups: items sharing a `group` id render as a
  single segmented pill (e.g. Light/Dark/System triple).
- Fullscreen mode: press "f" to hide all bottom chrome, Esc to exit.
- QuickInputBar + bottom bar visibility toggles via new pills.
- Progress ring on AI trigger pill during model download
  (conic-gradient ::after, follows pill border-radius).

@mana/local-stt — new package for browser-local speech-to-text:
- Whisper models via transformers.js v4 (WebGPU + WASM fallback)
- Same Web Worker architecture as @mana/local-llm
- Two models: Whisper Tiny (150 MB) and Whisper Small (950 MB)
- Reactive Svelte 5 bindings (getLocalSttStatus, loadLocalStt, transcribe)

Voice-to-text integration:
- useLocalStt() composable: mic capture via AudioContext +
  ScriptProcessor, resample to 16kHz mono, feed into Whisper worker
- Mic button in QuickInputBar (leftAction slot) with
  recording/loading/transcribing states + pulse animation
- Transcribed text injected into InputBar via new injectedText prop
- STT model selector in AI bar alongside LLM tier controls

Also: vite.config.ts server.fs.allow expanded to monorepo root
so workspace package workers resolve in dev.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -146,6 +146,7 @@ MinIO (Docker, S3-compatible) in both local and prod. Console: http://localhost:
 | `@mana/shared-i18n` | i18n |
 | `@mana/local-store` | Local-first store primitives — used by unified Mana, manavoxel, arcade, and shared-uload/-stores/-links |
 | `@mana/local-llm` | Browser-local LLM inference (transformers.js + Gemma 4 E2B, WebGPU). Powers `/llm-test` and the playground module. See [`packages/local-llm/CLAUDE.md`](packages/local-llm/CLAUDE.md) for the CSP requirements and the transformers.js v4 gotchas. |
+| `@mana/local-stt` | Browser-local speech-to-text (transformers.js + Whisper, WebGPU). Powers the QuickInputBar mic button. Same architecture as local-llm. See [`packages/local-stt/CLAUDE.md`](packages/local-stt/CLAUDE.md). |
 
 ## Adding Dependencies