feat: local LLM multi-model, session search, cron proactive types, notifications, docs overhaul

Local LLM:
- user_settings.py: per-user hosts/models config (local_llm.json)
- routers/local_llm.py + static/local_llm.html: dedicated settings page
- llm_client.py: local OpenAI-compatible backend via httpx
- config.py: LOCAL_API_URL/KEY/MODEL + per-backend timeouts
- Active model shown near backend toggle (amber hint text)

Memory distillation:
- memory_distiller.py: DISTILL_BACKEND_MID/LONG .env overrides
- scheduler.py + notification.py: notify NC Talk after mid/long distill
- notification.py: outbound channel abstraction (NC Talk, extensible)

Session search:
- routers/files.py: GET /sessions/search?q= with excerpts grouped by date
- static/index.html + app.js: search UI in file sidebar with highlight
- _esc() helper to prevent XSS in search results

Proactive cron:
- cron_runner.py: new job types — message (send directly) and brief (LLM + send)
- Both support optional per-job channel override

Channels:
- routers/nextcloud_talk.py: consolidated using notification._send_nct_message()
- routers/auth.py: local backend status in /auth/status
- routers/chat.py: /backend returns {primary, fallback, local_model} object

UI / UX:
- Copy button for user messages (matching assistant)
- Autocomplete disabled on sensitive form fields
- settings.html: local model section replaced with link to /settings/local

Docs overhaul:
- MASTER.md hub + ARCH__SYSTEM/BACKENDS/PERSONA/CHANNELS/FUTURE.md
- ARCH__Intelligence_Layer.md replaced with redirect table
- CORTEX.md trimmed to vision only; README updated
- OPEN_WEBUI_API.md added to docs/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cortex/notification.py

@@ -0,0 +1,106 @@
+"""
+Outbound notification helpers — send messages to user channels proactively.
+
+Channel config lives in home/{user}/channels.json.
+Each channel that supports proactive notifications needs a notification_channel
+set to its key name (e.g. "nextcloud", "google_chat") in the user's channels.json:
+  {
+    "notification_channel": "nextcloud",
+    "nextcloud": {
+      "url": "https://cloud.example.com",
+      "bot_secret": "...",
+      "notification_room": "<room-token>",
+      ...
+    }
+  }
+
+If notification_channel is absent, defaults to "nextcloud" if configured.
+If notification_room (for NCT) is absent, notifications are silently skipped.
+"""
+import hashlib
+import hmac
+import json
+import logging
+import secrets
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+
+async def _send_nct_message(url: str, secret: str, room: str, message: str) -> None:
+    """Post a message to a Nextcloud Talk room as the bot."""
+    endpoint = f"{url}/ocs/v2.php/apps/spreed/api/v1/bot/{room}/message"
+    random_str = secrets.token_hex(32)
+    sig = hmac.new(
+        secret.encode(),
+        (random_str + message).encode("utf-8"),
+        hashlib.sha256,
+    ).hexdigest()
+    body = json.dumps({"message": message}, ensure_ascii=False).encode("utf-8")
+
+    try:
+        async with httpx.AsyncClient() as client:
+            resp = await client.post(
+                endpoint,
+                content=body,
+                headers={
+                    "Content-Type": "application/json",
+                    "OCS-APIRequest": "true",
+                    "X-Nextcloud-Talk-Bot-Random": random_str,
+                    "X-Nextcloud-Talk-Bot-Signature": sig,
+                },
+                timeout=15,
+            )
+        if resp.status_code not in (200, 201):
+            logger.warning("notify NCT %s → HTTP %d: %s", room, resp.status_code, resp.text[:200])
+        else:
+            logger.info("notify NCT → %s (%d chars)", room, len(message))
+    except Exception as e:
+        logger.error("notify NCT error: %s", e)
+
+
+async def _notify_nct(nct: dict, message: str, username: str) -> None:
+    room   = nct.get("notification_room", "").strip()
+    url    = nct.get("url", "").rstrip("/")
+    secret = nct.get("bot_secret", "")
+    if not room:
+        logger.debug("notify: NCT notification_room not set for %s — skipping", username)
+        return
+    if not url or not secret:
+        logger.warning("notify: NCT config incomplete for %s (missing url or secret)", username)
+        return
+    await _send_nct_message(url, secret, room, message)
+
+
+async def notify(username: str, message: str, channel: str | None = None) -> None:
+    """Send a notification to the user's preferred outbound channel.
+
+    Channel resolution order:
+      1. `channel` parameter if provided
+      2. `notification_channel` key in channels.json
+      3. "nextcloud" if configured
+      4. Silent no-op
+
+    To configure: set `notification_channel` in home/{user}/channels.json.
+    For NCT: also set `notification_room` in the nextcloud section.
+    """
+    from auth_utils import get_user_channels
+    channels = get_user_channels(username)
+
+    target = channel or channels.get("notification_channel", "").strip()
+    if not target:
+        # Auto-detect: use nextcloud if configured
+        if "nextcloud" in channels:
+            target = "nextcloud"
+        else:
+            return
+
+    if target == "nextcloud":
+        nct = channels.get("nextcloud")
+        if not nct:
+            logger.debug("notify: nextcloud not configured for %s", username)
+            return
+        await _notify_nct(nct, message, username)
+    else:
+        logger.debug("notify: channel %r not yet supported for outbound (user %s)", target, username)