feat: http_post tool, nc_talk_history tool, local orchestrator retry

- http_post: POST to external URLs with per-user URL prefix allowlist
  (home/{user}/http_allowlist.json); admin-only, confirm-required
- nc_talk_history: read recent NC Talk messages via Basic Auth (requires
  nc_username + nc_app_password in channels.json under nextcloud)
- openai_orchestrator: _chat_with_retry() wraps both API calls with
  exponential backoff (3 attempts, 1s/2s) on connection errors and
  transient status codes (429, 500, 502, 503, 504)
- Docs updated: CLAUDE.md, HELP.md, TODO, MASTER, ROADMAP (50 tools)

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

cortex/tools/notify.py

@@ -10,6 +10,7 @@ import json
 import logging
 import re
 
+import httpx
 from google.genai import types
 from config import settings
 from persona import get_user
@@ -77,6 +78,74 @@ async def web_push(title: str, body: str, url: str = "") -> str:
     return f"Push sent to {result['sent']} device(s) for {username} (pruned {result['pruned']} stale)."
 
 
+async def nc_talk_history(conversation_token: str = "", limit: int = 20) -> str:
+    """Read recent messages from a Nextcloud Talk conversation.
+
+    Requires nc_username and nc_app_password in channels.json under 'nextcloud'.
+    conversation_token defaults to notification_room if not specified.
+    """
+    from auth_utils import get_user_channels
+    username = get_user()
+    channels = get_user_channels(username)
+    nct = channels.get("nextcloud", {})
+
+    url = nct.get("url", "").rstrip("/")
+    nc_username = nct.get("nc_username", "").strip()
+    nc_app_password = nct.get("nc_app_password", "").strip()
+    token = conversation_token.strip() or nct.get("notification_room", "").strip()
+
+    if not url or not nc_username or not nc_app_password:
+        return (
+            "nc_talk_history requires nc_username and nc_app_password in channels.json "
+            f"(under 'nextcloud'). Add these to home/{username}/channels.json to enable message reading."
+        )
+    if not token:
+        return "No conversation token provided and no notification_room set in channels.json."
+
+    limit = min(max(int(limit), 1), 200)
+    return await asyncio.to_thread(_sync_nc_talk_history, url, nc_username, nc_app_password, token, limit)
+
+
+def _sync_nc_talk_history(url: str, nc_user: str, nc_pass: str, token: str, limit: int) -> str:
+    from datetime import datetime, timezone
+    endpoint = f"{url}/ocs/v2.php/apps/spreed/api/v4/chat/{token}"
+    try:
+        resp = httpx.get(
+            endpoint,
+            params={"limit": limit, "lookIntoFuture": 0, "setReadMarker": 0, "noStatusUpdate": 1},
+            auth=(nc_user, nc_pass),
+            headers={"OCS-APIRequest": "true", "Accept": "application/json"},
+            timeout=15,
+        )
+    except Exception as e:
+        return f"NC Talk API error: {e}"
+
+    if resp.status_code != 200:
+        return f"NC Talk API returned HTTP {resp.status_code}: {resp.text[:200]}"
+
+    try:
+        messages = resp.json().get("ocs", {}).get("data", [])
+    except Exception as e:
+        return f"Failed to parse NC Talk response: {e}"
+
+    if not messages:
+        return "No messages found in this conversation."
+
+    # NC Talk returns newest-first; reverse to chronological order
+    lines = [f"Last {len(messages)} messages from {token}:\n"]
+    for msg in reversed(messages):
+        sender = msg.get("actorDisplayName") or msg.get("actorId") or "Unknown"
+        ts = msg.get("timestamp", 0)
+        time_str = datetime.fromtimestamp(ts, tz=timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
+        text = msg.get("message", "")
+        if msg.get("messageType") == "system":
+            lines.append(f"[system {time_str}] {text}")
+        else:
+            lines.append(f"{sender} ({time_str}): {text}")
+
+    return "\n".join(lines)
+
+
 async def nc_talk_send(message: str) -> str:
     """Send a message to the user via their configured notification channel.
 
@@ -145,4 +214,21 @@ DECLARATIONS = [
             required=["message"],
         ),
     ),
+    types.FunctionDeclaration(
+        name="nc_talk_history",
+        description=(
+            "Read recent messages from a Nextcloud Talk conversation. Useful for checking "
+            "what was said in a room before composing a reply, or reviewing recent context. "
+            "Requires nc_username and nc_app_password in channels.json under 'nextcloud'. "
+            "conversation_token defaults to notification_room if not provided."
+        ),
+        parameters=types.Schema(
+            type=types.Type.OBJECT,
+            properties={
+                "conversation_token": types.Schema(type=types.Type.STRING, description="NC Talk room token (defaults to notification_room from channels.json)"),
+                "limit":              types.Schema(type=types.Type.INTEGER, description="Number of messages to return (default 20, max 200)"),
+            },
+            required=[],
+        ),
+    ),
 ]