feat: resolve dynamic token limits from LiteLLM; unify context usage UI

feat: track STT/TTS models in session; fix audio progress bar; add token usage bar

fix: implement global settings fallback for LLM provider in RAG chat; allow fuzzy model name matching

fix: implement system-settings fallback in STT/TTS routes and resolve missing key 500 error

fix: relax provider health checks and allow non-admin verification for self-provided keys

fix: resolve STT/TTS provider resolution for anonymous/unauthenticated sessions

fix: resolve 'no active stt provider' by ensuring global settings fallback even without user preferences

debug: add verbose TTS logging and strict concurrency of 1 to isolate Google 500 errors

feat: adaptive TTS chunking for lower latency and better stream stability

feat: implement intelligent multi-sentence splitting to eliminate TTS streaming gaps

fix: resolve NameError for logger in TTS route

fix: resolve TTS streaming interruptions via atomic state management and Proxy timeout disabling

chore: cleanup test scripts, secure deployment script, and implement Voice/TTS frontend refinements ...

- Removed all temporary root Python test scripts
- Secured remote_deploy.sh credentials using environment variables
- Added data/audio payloads directory to .gitignore
- Added automatic DB migration script (migrate.py) via uvicorn lifespan
- Applied major refactors to UI Voice Chat, Session handling, and unified React API configs
- Updated models and dependencies natively syncing with Nginx proxy features

feat: expose model info to users, multi-model provider cloning, cleaner profile UI ...

- Show model name under each provider button for all users (ProfilePage)
- Admin Settings: upgraded 'Register New Instance' panel with 4 fields:
  provider type, label suffix (with model-name hint), pre-set model
  dropdown, and 'Inherit API Key From' for same-type instance cloning
- Fix API key inheritance: use _clone_from marker instead of copying
  masked key; backend resolves real key from DB before saving
- Lock cloned-key instances: API key field is greyed out with lock icon
  and 'Inherited from <source>' display; Unlink button breaks the link
- Provider card header: show configured model name instead of
  'User Override / System Provided' labels
- ProfilePage: remove confusing 'Do Extra Work' override panel entirely;
  ServiceSelect is now a clean provider selector with no hidden admin UI
- SettingsPage: remove 'User Override' / 'System Provided' badge

Refactor STT model selection to dropdown, add YAML config import/export, and refine Voice/Coding Assistant UI

feat: session history sidebar with feature isolation and auto-titling ...

Backend changes:
- db/models.py: add feature_name column to Session model
- db/models.py: confirmed is_archived col for soft-delete support
- api/schemas.py: expose feature_name on SessionCreate and Session schemas
- core/services/session.py: accept feature_name in create_session()
- api/routes/sessions.py: pass feature_name on creation; add GET /sessions/
  (filtered by user + feature), DELETE /sessions/{id}, DELETE /sessions/
- core/services/rag.py: auto-title session from first user message;
  keep session.provider_name in sync with the model actually used
- core/services/workspace.py: same auto-title + provider_name sync
  on the WebSocket chat path

Frontend changes:
- services/apiService.js: createSession() now sends feature_name and
  provider_name; add getUserSessions(), deleteSession(), deleteAllSessions()
- services/websocket.js: getSessionId() accepts providerName and forwards
  it to createSession so the DB record reflects the real model
- hooks/useCodeAssistant.js: pass 'coding_assistant' namespace + 'deepseek'
  provider; expose handleSwitchSession + sessionId to page
- hooks/useVoiceChat.js: pass 'voice_chat' namespace + 'gemini' provider;
  expose handleSwitchSession + sessionId to page
- components/SessionSidebar.js: new collapsible sidebar (collapsed by default)
  showing history sessions per feature; click to switch, hover to see token
  usage tooltip, per-card delete and bulk 'Clear All'; shows smart relative
  date and provider badge per session
- components/SessionSidebar.css: theme-aware CSS (inherits Tailwind
  light/dark palette; no forced dark mode)
- pages/CodingAssistantPage.js: mount SessionSidebar with coding_assistant
- pages/VoiceChatPage.js: mount SessionSidebar with voice_chat

Tests:
- tests/core/services/test_session_service.py: new unit tests for
  SessionService covering feature_name namespace variants and DB rollback
- tests/api/routes/test_sessions.py: unit tests for new session mgmt routes
  (list by feature, single delete, bulk delete, token usage)
- integration_tests/test_sessions_api.py: end-to-end tests for feature
  isolation, single delete, 404 on missing session, and bulk delete
  confirming cross-feature sessions are unaffected

feat: Add new session UI, token counter, load history, and session isolation

add go-to-production code

enable OIDC

refactor general router

refactor the service container

use litellm underlying

add some logic in workspace

reactor ui project

introduce gcloud tts

add demo code & cors enabled & document the apis

introduce stt endpoint

refactor the routes api to be more modularized