feat: host inventory (agent.inventory), host detail page, UI columns

Store hardware/software snapshots on hosts; warn on hardware changes. Host card from Hosts list. Add agent version column to Events/Overview; rename Hosts table columns and sort by status.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/api/v1/hosts.py

@@ -7,7 +7,7 @@ from app.auth.jwt_auth import get_current_user, require_admin
 from app.config import get_settings
 from app.database import get_db
 from app.models import Event, Host
-from app.schemas.list_models import HostListResponse, HostSummary
+from app.schemas.list_models import HostDetail, HostListResponse, HostSummary
 from app.services.host_delete import delete_host_and_related
 from app.services.host_health import (
     HEARTBEAT_TYPE,
@@ -63,6 +63,7 @@ def list_hosts(
                 hostname=host.hostname,
                 display_name=host.display_name,
                 os_family=host.os_family,
+                os_version=host.os_version,
                 product=host.product,
                 product_version=host.product_version,
                 ipv4=host.ipv4,
@@ -70,6 +71,7 @@ def list_hosts(
                 event_count=int(event_count or 0),
                 last_heartbeat_at=last_hb,
                 last_daily_report_at=report_map.get(host.id),
+                last_inventory_at=host.inventory_updated_at,
                 agent_status=agent_status(
                     last_hb, stale_minutes=settings.sac_heartbeat_stale_minutes
                 ),
@@ -79,6 +81,56 @@ def list_hosts(
     return HostListResponse(items=items, total=total, page=page, page_size=page_size)
 
 
+def _host_detail_from_model(
+    host: Host,
+    *,
+    db: Session,
+    settings,
+) -> HostDetail:
+    hb_map = max_event_time_by_host(db, HEARTBEAT_TYPE)
+    report_map = max_daily_report_time_by_host(db)
+    event_count = db.scalar(
+        select(func.count()).select_from(Event).where(Event.host_id == host.id)
+    )
+    last_hb = hb_map.get(host.id)
+    return HostDetail(
+        id=host.id,
+        hostname=host.hostname,
+        display_name=host.display_name,
+        os_family=host.os_family,
+        os_version=host.os_version,
+        product=host.product,
+        product_version=host.product_version,
+        ipv4=host.ipv4,
+        ipv6=host.ipv6,
+        last_seen_at=host.last_seen_at,
+        event_count=int(event_count or 0),
+        last_heartbeat_at=last_hb,
+        last_daily_report_at=report_map.get(host.id),
+        last_inventory_at=host.inventory_updated_at,
+        agent_status=agent_status(last_hb, stale_minutes=settings.sac_heartbeat_stale_minutes),
+        agent_instance_id=host.agent_instance_id,
+        tags=host.tags if isinstance(host.tags, list) else [],
+        use_sac_mode=host.use_sac_mode,
+        inventory=host.inventory if isinstance(host.inventory, dict) else None,
+        inventory_updated_at=host.inventory_updated_at,
+        created_at=host.created_at,
+    )
+
+
+@router.get("/{host_id}", response_model=HostDetail)
+def get_host(
+    host_id: int,
+    db: Session = Depends(get_db),
+    _user: str = Depends(get_current_user),
+) -> HostDetail:
+    host = db.get(Host, host_id)
+    if host is None:
+        raise HTTPException(status_code=404, detail="Host not found")
+    settings = get_settings()
+    return _host_detail_from_model(host, db=db, settings=settings)
+
+
 class HostDeleteResponse(BaseModel):
     status: str
     host_id: int