feat: exclude Teams from defaults + GUID resolution in explain

- Add Teams to noisy services excluded by default (frontend + backend ask)
- Exchange, SharePoint, and Teams now unchecked by default in filters
- Enhance explain endpoint with GUID resolution:
  * Extract UUIDs from raw event JSON recursively
  * Resolve directory objects via Graph API (user, group, SP, device)
  * Include resolved names in LLM prompt so explanations reference
    human-readable names instead of raw GUIDs
- Add asyncio import for to_thread wrapper around sync Graph calls

backend/frontend/index.html

@@ -522,7 +522,7 @@
             const saved = localStorage.getItem('aoc_filters');
             if (!saved && this.options.services.length) {
               // Default: exclude noisy high-volume services
-              const noisy = ['Exchange', 'SharePoint'];
+              const noisy = ['Exchange', 'SharePoint', 'Teams'];
               this.filters.selectedServices = this.options.services.filter((s) => !noisy.includes(s));
             } else if (saved) {
               try {
@@ -617,7 +617,7 @@
         },
 
         clearFilters() {
-          const noisy = ['Exchange', 'SharePoint'];
+          const noisy = ['Exchange', 'SharePoint', 'Teams'];
           this.filters = { actor: '', selectedServices: this.options.services.filter((s) => !noisy.includes(s)), search: '', operation: '', result: '', start: '', end: '', limit: 100, includeTags: '', excludeTags: '' };
           this.saveFilters();
           this.resetPagination();

backend/routes/ask.py

@@ -1,3 +1,4 @@
+import asyncio
 import json
 import re
 from datetime import UTC, datetime, timedelta
@@ -49,7 +50,7 @@ _SERVICE_INTENTS = {
 
 # Services that are extremely noisy for typical admin questions.
 # We exclude them by default on broad questions unless the user explicitly mentions them.
-_NOISY_SERVICES = {"Exchange", "SharePoint"}
+_NOISY_SERVICES = {"Exchange", "SharePoint", "Teams"}
 
 # Services that are generally admin-relevant and kept by default.
 _DEFAULT_ADMIN_SERVICES = {
@@ -471,11 +472,73 @@ Do not invent facts that are not in the data.
 """
 
 
+_GUID_RE = re.compile(r"^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$")
+
+
+def _extract_guids(obj: dict | list | str) -> set[str]:
+    """Recursively extract UUID-like strings from a JSON structure."""
+    guids = set()
+    if isinstance(obj, dict):
+        for k, v in obj.items():
+            if k.lower() in ("id", "groupid", "userid", "targetid") and isinstance(v, str) and _GUID_RE.match(v):
+                guids.add(v)
+            guids.update(_extract_guids(v))
+    elif isinstance(obj, list):
+        for item in obj:
+            guids.update(_extract_guids(item))
+    elif isinstance(obj, str) and _GUID_RE.match(obj):
+        guids.add(obj)
+    return guids
+
+
+async def _resolve_guids_for_event(event: dict) -> dict[str, str]:
+    """Try to resolve GUIDs in an event to human-readable names via Graph API."""
+    raw = event.get("raw") or {}
+    guids = _extract_guids(raw)
+    # Also include any GUIDs in targetResources that might not have displayName
+    for tr in raw.get("targetResources") or []:
+        tid = tr.get("id")
+        if tid and _GUID_RE.match(tid):
+            guids.add(tid)
+    for tr in raw.get("modifiedProperties") or []:
+        for key in ("oldValue", "newValue"):
+            val = tr.get(key)
+            if val and _GUID_RE.match(val):
+                guids.add(val)
+
+    if not guids:
+        return {}
+
+    try:
+        from graph.auth import get_access_token
+        from graph.resolve import resolve_directory_object
+
+        token = await asyncio.to_thread(get_access_token)
+        cache: dict[str, dict] = {}
+        resolved = {}
+        for gid in guids:
+            result = await asyncio.to_thread(resolve_directory_object, gid, token, cache)
+            if result:
+                resolved[gid] = result["name"]
+        return resolved
+    except Exception as exc:
+        logger.warning("GUID resolution failed", error=str(exc))
+        return {}
+
+
 async def _explain_event(event: dict, related: list[dict]) -> str:
     if not LLM_API_KEY:
         raise RuntimeError("LLM_API_KEY not configured")
 
+    # Resolve GUIDs to names before sending to LLM
+    resolved = await _resolve_guids_for_event(event)
+
     event_text = json.dumps(event, indent=2, default=str)
+    resolution_text = ""
+    if resolved:
+        resolution_text = "\nResolved GUIDs:\n"
+        for gid, name in resolved.items():
+            resolution_text += f"  {gid} → {name}\n"
 
     related_text = ""
     if related:
@@ -492,7 +555,7 @@ async def _explain_event(event: dict, related: list[dict]) -> str:
         {"role": "system", "content": _EXPLAIN_SYSTEM_PROMPT},
         {
             "role": "user",
-            "content": f"Audit event:\n{event_text}{related_text}\n\nPlease explain this event.",
+            "content": f"Audit event:\n{event_text}{resolution_text}{related_text}\n\nPlease explain this event.",
         },
     ]