Fix 3 arc reactor bugs: metrics_json→metric_data, system nesting, message→content in conversations

- guardian_loop + sitrep: SELECT metric_data (not metrics_json which does not exist)
- guardian_loop: metrics are flat (cpu_percent at top level), not nested under system key
- guardian_loop + sitrep: filter metric_type=system to avoid parsing proxmox blobs
- guardian_loop: disk.mount key (not mountpoint) + fallback for both key names
- sitrep: same metric_data + root-level key fixes
- _guardian_inject_chat (x2): INSERT into conversations.content (not message)
- /guardian/chat endpoint (x2): SELECT content (not message) from conversations

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

agent/jarvis-arc-reactor.py

@@ -945,10 +945,11 @@ async def guardian_loop() -> None:
             # ── 2. Metrics analysis ───────────────────────────────────────────
             # Get latest metric per online agent
             metrics_rows = await db_fetchall(
-                """SELECT m.agent_id, r.hostname, m.metrics_json
+                """SELECT m.agent_id, r.hostname, m.metric_data
                    FROM agent_metrics m
                    JOIN registered_agents r ON r.agent_id = m.agent_id
                    WHERE r.status = 'online'
+                     AND m.metric_type = 'system'
                      AND m.recorded_at > DATE_SUB(NOW(), INTERVAL 5 MINUTE)
                    ORDER BY m.recorded_at DESC"""
             )
@@ -961,8 +962,7 @@ async def guardian_loop() -> None:
                 hostname = row["hostname"]
 
                 try:
-                    m = json.loads(row["metrics_json"]) if isinstance(row["metrics_json"], str) else row["metrics_json"]
+                    sys_data = json.loads(row["metric_data"]) if isinstance(row["metric_data"], str) else row["metric_data"]
-                    sys_data = m.get("system", {})
 
                     cpu = sys_data.get("cpu_percent")
                     if cpu is not None and float(cpu) >= cpu_thresh:
@@ -988,7 +988,7 @@ async def guardian_loop() -> None:
                         for disk in disks:
                             dpct = disk.get("percent", 0)
                             if dpct and float(str(dpct).rstrip("%")) >= disk_thresh:
-                                mount = disk.get("mountpoint", "/")
+                                mount = disk.get("mount", disk.get("mountpoint", "/"))
                                 key   = f"disk_{mount}"
                                 if await _guardian_cooldown_ok(aid, key):
                                     msg = f"{hostname}: Disk {mount} at {dpct}% (threshold: {disk_thresh}%)"
@@ -1051,7 +1051,7 @@ async def _guardian_inject_chat(message: str) -> None:
     """Write a proactive JARVIS message into the conversations table so the HUD picks it up."""
     try:
         await db_execute(
-            """INSERT INTO conversations (session_id, role, message, created_at)
+            """INSERT INTO conversations (session_id, role, content, created_at)
                VALUES ('guardian', 'assistant', %s, NOW())""",
             (message,)
         )
@@ -1079,16 +1079,16 @@ async def handle_sitrep(payload: dict) -> dict:
     # 2. Get latest metrics per agent
     metrics_map = {}
     metrics_rows = await db_fetchall(
-        """SELECT m.agent_id, m.metrics_json, m.recorded_at
+        """SELECT m.agent_id, m.metric_data, m.recorded_at
            FROM agent_metrics m
-           WHERE m.recorded_at > DATE_SUB(NOW(), INTERVAL 10 MINUTE)
+           WHERE m.metric_type = 'system'
+             AND m.recorded_at > DATE_SUB(NOW(), INTERVAL 10 MINUTE)
            ORDER BY m.recorded_at DESC"""
     )
     for row in metrics_rows:
         if row["agent_id"] not in metrics_map:
             try:
-                m = json.loads(row["metrics_json"]) if isinstance(row["metrics_json"], str) else row["metrics_json"]
+                metrics_map[row["agent_id"]] = json.loads(row["metric_data"]) if isinstance(row["metric_data"], str) else row["metric_data"]
-                metrics_map[row["agent_id"]] = m
             except Exception:
                 pass
 
@@ -1117,7 +1117,7 @@ async def handle_sitrep(payload: dict) -> dict:
         sys  = m.get("system", {}) if m else {}
         cpu  = sys.get("cpu_percent", "?")
         mem  = sys.get("memory", {}).get("percent", "?") if isinstance(sys.get("memory"), dict) else "?"
-        disk = next((d.get("percent","?") for d in (sys.get("disk") or []) if d.get("mountpoint") == "/"), "?")
+        disk = next((d.get("percent","?") for d in (sys.get("disk") or []) if d.get("mount","").rstrip("/") == "" or d.get("mountpoint","") == "/"), "?")
         line = (f"  {ag['hostname']} ({ag['status'].upper()}) — "
                 f"CPU:{cpu}% MEM:{mem}% DISK:{disk}%")
         agent_lines.append(line)
@@ -1806,7 +1806,7 @@ Keep the tone confident and action-oriented. Format with clear sections. Under 4
 
     # Store in conversations so HUD can surface it
     await db_execute(
-        "INSERT INTO conversations (session_id, role, message, created_at) VALUES ('guardian','assistant',%s,NOW())",
+        "INSERT INTO conversations (session_id, role, content, created_at) VALUES ('guardian','assistant',%s,NOW())",
         (review_text,)
     )
 
@@ -2728,13 +2728,13 @@ async def guardian_chat_events(since: str = ""):
     """Return proactive guardian messages injected into conversations."""
     if since:
         rows = await db_fetchall(
-            "SELECT id, message, created_at FROM conversations "
+            "SELECT id, content, created_at FROM conversations"
             "WHERE session_id='guardian' AND created_at > %s ORDER BY created_at ASC",
             (since,)
         )
     else:
         rows = await db_fetchall(
-            "SELECT id, message, created_at FROM conversations "
+            "SELECT id, content, created_at FROM conversations"
             "WHERE session_id='guardian' ORDER BY created_at DESC LIMIT 10"
         )
     return rows or []