[pending-judge] feat(DC-163): AI assistant that works — LLM intent engine + fixed chat panel

The floating assistant was broken end-to-end; Sami said "Do it that works".
Three user-visible bugs fixed + the promised LLM delegation implemented:

FRONTEND (status/js/ai-chat.js — rewritten):
- Response parsing: old code read data.data; the API returns the FLAT ok()
  envelope — EVERY reply rendered "Sorry, something went wrong". Now reads
  the real shape (contract asserted by route test).
- Suggestion chips: onclick="...send('"Deploy Plex"')" — nested quotes,
  invalid JS, dead buttons (shipped like this). Now data-driven buttons with
  addEventListener.
- Deploy button: called window.openAppSelector which NEVER existed anywhere
  in the tree (grep-verified). Now opens the REAL deploy modal via new
  window.openDeployConfigFor(templateId) exported by app-selector.js —
  resolves against the live API template cache, reuses showDeployConfig
  (same path a manual catalog click takes). Widgets route to the grid.
- Conversation history (last 6 turns) now rides along per request, engine
  badge in header, ⚙ settings sub-panel (baseUrl/model/API key + Test +
  Remove), all server text via textContent (no HTML injection), CSP-safe
  (no inline handlers).

BACKEND (routes/ai-intent.js):
- TWO engines, one contract. LLM classifier (OpenAI-compatible chat
  completions) with system prompt embedding the LIVE 78-app catalog + the
  six wizard categories; regex patterns kept as the zero-config default and
  the automatic failover (HTTP error, timeout via AbortController,
  unparseable output -> pattern answers; response carries engine +
  llmError so the UI can say which served — no silent degradation).
- Closed-vocabulary schema validation: intent MUST be in the known set else
  'unknown'; appId MUST exist in APP_TEMPLATES else nulled (hallucinated
  ids cannot leak into deploy plans); categories filtered to the wizard's
  real keys; reply stripped of control chars + bounded to 600; history
  role-filtered (only user/assistant pass — client-injected system turns
  dropped) + capped; input capped to 1000 chars.
- enrich() rebuilds the response contract per intent; pattern-canned
  response is dropped when the LLM rerouted the intent (no stale shape);
  deployPlan body.port now fills from the template's defaultPort (was
  hardcoded null); deployPlan shape asserted against wizard usage.
- Key storage: PUT /ai/settings stores {baseUrl,model,apiKey} in the
  ENCRYPTED credential store (key 'ai:llm') via ctx.credentialManager —
  NOT config.json (GET /config echoes the raw file to the browser; that
  route's shape was verified before this decision). Blank apiKey on PUT
  keeps the stored one. GET /ai/settings reports configured/source/model/
  hasApiKey — the key value NEVER crosses the wire (asserted). Env
  fallback AI_LLM_BASE_URL/AI_LLM_API_KEY/AI_LLM_MODEL + legacy
  LLM_PROXY_URL for headless installs. POST /ai/settings/test = one-shot
  real classify probe returning ok/sample or ok:false/reason (never
  throws). DELETE clears.
- GET /ai/capabilities now reports engine + llm status (pattern was honest
  marketing before; now it can be true).

MOUNT (src/app.js): aiIntentRoutes receives siteConfig, log, fetchImpl
(ctx.fetchT — test-injectable) and credentialManager.

Docs: OpenAPI +4 AI path entries (intent, capabilities, settings, settings/test); CHANGELOG entry; dist bundle rebuilt
(openDeployConfigFor present in features.js; SW cache c62511c40d).

Tests: 20 NEW in __tests__/routes/ai-intent-engine.test.js (engine
selection w/ and w/o store, off-catalog phrasing via mock LLM,
hallucinated-id nulling, illegal intent coercion, HTTP-500 failover,
AbortError timeout failover, markdown-fence repair, reply sanitization,
history cap+role filter, env config path, intent-disagreement rebuild w/
real jellyfin port 8096, flat envelope contract, 400s, 1000-char cap,
settings GET/PUT/DELETE/test incl. key-never-echoed assertions,
capabilities engine reporting) + the 18 original pattern tests unchanged +
composition-root e2e 8 pass. Full suite: 3643 passed; only the pre-existing
pdf-parse billing family red (6 failed in documented band [5,7], patch
touches no billing file).

dashcaddy-api/openapi.yaml

@@ -7773,6 +7773,71 @@ paths:
         '200':
           description: Probe result (ok flag inside — transport errors are reported, not thrown)
 
+  /api/v1/ai/intent:
+    post:
+      tags: [AI]
+      summary: Natural language → structured intent
+      description: >
+        Dual-engine intent router. LLM engine (OpenAI-compatible classifier,
+        configured via /ai/settings or AI_LLM_* env) resolves against the
+        full app catalog and conversation history; pattern engine serves
+        offline and as automatic failover (engine field tells which answered;
+        llmError records the failover reason). Output is schema-validated
+        against closed vocabularies — the model can never emit an action or
+        template id outside the platform's real sets. Response is the flat
+        ok() envelope: {success, intent, confidence, action, engine, appId?,
+        serviceId?, response{message,appId?,appName?,recommendations?,
+        suggestions?,disclaimer?}, deployPlan?, wizardCall?, timestamp}.
+      responses:
+        '200':
+          description: Structured intent (flat envelope)
+        '400':
+          description: message (non-empty string) required
+
+  /api/v1/ai/capabilities:
+    get:
+      tags: [AI]
+      summary: What the assistant can do + live engine status
+      responses:
+        '200':
+          description: Intent list, capabilities, engine (llm|pattern), llm config status (key never included)
+
+  /api/v1/ai/settings:
+    get:
+      tags: [AI]
+      summary: LLM assistant configuration (key never echoed)
+      responses:
+        '200':
+          description: configured, source, baseUrl, model, hasApiKey
+    put:
+      tags: [AI]
+      summary: Store LLM config in the encrypted credential store
+      description: >
+        body {baseUrl?, model?, apiKey?}. Stored under credential key
+        'ai:llm' — NEVER config.json (GET /config returns the raw file to
+        the browser). Blank apiKey keeps the stored one. First save
+        requires baseUrl + apiKey. baseUrl must be http(s).
+      responses:
+        '200':
+          description: Saved (response never contains the key)
+        '400':
+          description: Invalid baseUrl or missing required fields
+    delete:
+      tags: [AI]
+      summary: Remove stored LLM config (falls back to env/pattern)
+      responses:
+        '200':
+          description: Cleared
+
+  /api/v1/ai/settings/test:
+    post:
+      tags: [AI]
+      summary: One-shot classifier probe (proves the LLM end-to-end)
+      description: Sends a fixed sample message through the configured LLM and returns the parsed intent. Failures answer ok:false with a reason (200), never throw.
+      responses:
+        '200':
+          description: '{ok, engine, model?, sample?{intent,reply}} or {ok:false, reason}'
+
   /api/v1/mcp:
     post:
       tags: [MCP]