Add clear asset GPS endpoint + UI

- DELETE /api/assets/{id}/gps: clears lat/lng to NULL
- GET /api/assets/{id}: asset lookup by ID
- GET /api/assets/search?machine_id=: asset lookup by machine ID
- Export & Admin page: Clear Asset GPS card with lookup + confirmation
- Tests: 204 success + 404 not found

admin_server.py

@@ -1583,6 +1583,51 @@ def export_checkins_csv(asset_id: Optional[int] = Query(None)):
     )
 
 
+# ─── Asset GPS Management ──────────────────────────────────────────────────
+
+
+@app.get("/api/assets/{asset_id}")
+def get_asset_admin(asset_id: int):
+    """Get a single asset by ID (admin)."""
+    conn = get_db()
+    row = conn.execute("SELECT * FROM assets WHERE id = ?", (asset_id,)).fetchone()
+    conn.close()
+    if row is None:
+        raise HTTPException(status_code=404, detail="Asset not found")
+    return row_to_dict(row)
+
+
+@app.get("/api/assets/search")
+def search_assets_admin(machine_id: str = Query(...)):
+    """Search for an asset by machine_id (admin)."""
+    conn = get_db()
+    row = conn.execute(
+        "SELECT * FROM assets WHERE machine_id = ?", (machine_id,)
+    ).fetchone()
+    conn.close()
+    if row is None:
+        raise HTTPException(status_code=404, detail="Asset not found")
+    return row_to_dict(row)
+
+
+@app.delete("/api/assets/{asset_id}/gps", status_code=204)
+def clear_asset_gps(asset_id: int):
+    """Clear GPS coordinates from an asset (sets latitude/longitude to NULL)."""
+    conn = get_db()
+    existing = conn.execute("SELECT id, name FROM assets WHERE id = ?", (asset_id,)).fetchone()
+    if existing is None:
+        conn.close()
+        raise HTTPException(status_code=404, detail="Asset not found")
+    conn.execute(
+        "UPDATE assets SET latitude = NULL, longitude = NULL, updated_at = datetime('now') WHERE id = ?",
+        (asset_id,),
+    )
+    _log_activity(conn, "updated", "asset", asset_id,
+                  f"GPS data cleared for '{existing['name']}'")
+    conn.commit()
+    conn.close()
+
+
 # ─── Icon Upload API ────────────────────────────────────────────────────────