Add GPS-only backup/restore and database wipe

- Fix backup.py PRESERVED_FIELDS column names (lat/lng -> latitude/longitude)
  to match actual DB schema (pre-existing bug)
- Add backup_gps() and restore_gps() dedicated GPS-only functions
- Add /api/gps/backup and /api/gps/restore API endpoints
- Add /api/gps/restore/upload for restoring from uploaded backup files
- Add /api/db/wipe endpoint to clear all asset records
- Update UI with GPS-only Backup button, Restore GPS from File picker,
  and Wipe All Assets with double-confirmation dialog
- Fix backup listing to scan both seed-data/ and project root

web/server.py

@@ -43,8 +43,16 @@ from backup import backup as do_backup, compare as compare_backup
 
 
 def _list_backup_files() -> list[dict]:
-    """List backup files in the seed-data directory."""
-    files = sorted(glob.glob(str(PROJECT_ROOT / "seed-data" / "backup_*.json.gz")), reverse=True)
+    """List backup files in the seed-data directory OR project root."""
+    patterns = [
+        str(PROJECT_ROOT / "seed-data" / "backup_*.json.gz"),
+        str(PROJECT_ROOT / "backup_*.json.gz"),
+    ]
+    files = set()
+    for pat in patterns:
+        for f in glob.glob(pat):
+            files.add(f)
+    files = sorted(files, reverse=True)
     result = []
     for f in files:
         try:
@@ -446,6 +454,99 @@ async def api_restore(
         raise HTTPException(500, f"Restore error: {e}")
 
 
+# ─── GPS-only endpoints ───────────────────────────────────────────────────────
+
+
+@app.post("/api/gps/backup")
+async def api_gps_backup(db_path: str = Query(DEFAULT_DB_PATH)):
+    """Backup GPS data only (latitude, longitude) — ideal before wiping."""
+    if not os.path.exists(db_path):
+        raise HTTPException(404, f"Database not found: {db_path}")
+    try:
+        from backup import backup_gps as do_backup_gps
+        path = do_backup_gps(db_path)
+        _session_state["last_backup"] = path
+        return {"backup_path": path, "status": "ok", "type": "gps_only"}
+    except Exception as e:
+        traceback.print_exc()
+        raise HTTPException(500, f"GPS backup error: {e}")
+
+
+@app.post("/api/gps/restore")
+async def api_gps_restore(
+    backup_path: str = Query(...),
+    db_path: str = Query(DEFAULT_DB_PATH),
+):
+    """Restore GPS data only (latitude, longitude) from a GPS-only backup."""
+    if not os.path.exists(backup_path):
+        raise HTTPException(404, f"Backup not found: {backup_path}")
+    try:
+        from backup import restore_gps as do_restore_gps
+        do_restore_gps(backup_path, db_path)
+        return {"status": "ok", "restored_from": os.path.basename(backup_path), "db": db_path}
+    except Exception as e:
+        traceback.print_exc()
+        raise HTTPException(500, f"GPS restore error: {e}")
+
+
+@app.post("/api/gps/restore/upload")
+async def api_gps_restore_upload(
+    backup_file: UploadFile = File(...),
+    db_path: str = Query(DEFAULT_DB_PATH),
+):
+    """Upload a GPS backup file and restore it into the database."""
+    if not backup_file.filename:
+        raise HTTPException(400, "No file provided")
+    suffix = Path(backup_file.filename).suffix.lower()
+    if suffix not in (".gz", ".json"):
+        raise HTTPException(400, f"Unsupported file type: {suffix}. Upload .json.gz or .json")
+    try:
+        # Save to temp
+        import tempfile
+        tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".json.gz")
+        content = await backup_file.read()
+        tmp.write(content)
+        tmp_path = tmp.name
+        tmp.close()
+
+        from backup import restore_gps as do_restore_gps
+        do_restore_gps(tmp_path, db_path)
+
+        os.unlink(tmp_path)
+
+        return {"status": "ok", "restored_from": backup_file.filename, "db": db_path}
+    except Exception as e:
+        traceback.print_exc()
+        raise HTTPException(500, f"GPS restore error: {e}")
+
+
+# ─── Database management ───────────────────────────────────────────────────────
+
+
+@app.post("/api/db/wipe")
+async def api_db_wipe(db_path: str = Query(DEFAULT_DB_PATH)):
+    """Wipe all asset records from the database. Does NOT delete the file."""
+    if not os.path.exists(db_path):
+        raise HTTPException(404, f"Database not found: {db_path}")
+    try:
+        import sqlite3
+        conn = sqlite3.connect(db_path)
+        cur = conn.execute("SELECT COUNT(*) FROM assets")
+        before = cur.fetchone()[0]
+        conn.execute("DELETE FROM assets")
+        conn.commit()
+        conn.close()
+        return {
+            "status": "ok",
+            "records_deleted": before,
+            "db_path": db_path,
+            "note": "All asset records wiped. Database file preserved.",
+        }
+    except Exception as e:
+        traceback.print_exc()
+        raise HTTPException(500, f"Wipe error: {e}")
+
+
 # ─── Static files ─────────────────────────────────────────────────────────────
 
 STATIC_DIR = Path(__file__).parent / "static"