feat: tool risk policy UI + wiring through all orchestrators

- New /settings/tools page: max_risk selector (low/medium/high) + per-tool
  override dropdowns (Default / Force include / Force exclude) for all 58 tools
  grouped by category with color-coded risk badges; JS updates Auto status live
- get_tools_for_role() + get_openai_tools_for_role() now accept max_risk,
  whitelist, blacklist; _apply_risk_policy() handles the filtering logic
- get_risk_policy() helper in auth_utils reads from tool_policy.json
- Risk policy wired through orchestrator.py, openai_orchestrator.py,
  orchestrator_engine.py, nextcloud_talk.py, homeassistant.py
- Tools nav link added to settings.html and notifications.html
- CLAUDE.md and ARCH__SYSTEM.md updated: tool count 50→58, risk system docs,
  tool access control three-layer model documented

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

cortex/auth_utils.py

@@ -229,9 +229,14 @@ def get_user_channels(username: str) -> dict:
 def get_tool_policy(username: str) -> dict:
     """Return the parsed tool_policy.json for a user.
 
-    Keys:
-      allow — tools in CONFIRM_REQUIRED that this user has pre-approved (skip gate)
-      deny  — tools always blocked for this user regardless of global CONFIRM_REQUIRED
+    Confirmation-gate keys (existing):
+      allow     — tools in CONFIRM_REQUIRED that this user has pre-approved (skip gate)
+      deny      — tools always blocked for this user regardless of global CONFIRM_REQUIRED
+
+    Risk-policy keys (new):
+      max_risk  — auto-include all tools at/below this level ("low"|"medium"|"high")
+      whitelist — force-include specific tools above max_risk
+      blacklist — force-exclude specific tools regardless of max_risk
     """
     path = settings.home_root() / username / "tool_policy.json"
     try:
@@ -240,6 +245,16 @@ def get_tool_policy(username: str) -> dict:
         return {}
 
 
+def get_risk_policy(username: str) -> tuple[str | None, list[str], list[str]]:
+    """Return (max_risk, whitelist, blacklist) from the user's tool policy."""
+    policy = get_tool_policy(username)
+    return (
+        policy.get("max_risk") or None,
+        policy.get("whitelist") or [],
+        policy.get("blacklist") or [],
+    )
+
+
 def save_tool_policy(username: str, data: dict) -> None:
     path = settings.home_root() / username / "tool_policy.json"
     path.write_text(json.dumps(data, indent=2) + "\n")