Revert "Add clear GPS endpoint + frontend button"

This reverts commit ca77a29d7d.

server.py

@@ -1270,24 +1270,6 @@ def delete_asset(asset_id: int):
     conn.close()
 
 
-@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()
-
-
 # ─── Task 8: POST /api/checkins ─────────────────────────────────────────────