Add 2D barcode scanning + connect_id search

- Add QR_CODE, DATA_MATRIX, PDF_417, AZTEC to barcode scanner hints
  so serial number stickers with 2D barcodes can be scanned
- Update /api/assets/search to also match connect_id so full
  Connect IDs (e.g. VM-05912-0000068454) work when scanned
- Bump SW cache v5→v6, footer v3.2→v3.3

server.py

@@ -1129,7 +1129,8 @@ def list_assets(
 def search_by_machine_id(machine_id: str = Query(...)):
     conn = get_db()
     row = conn.execute(
-        "SELECT * FROM assets WHERE machine_id = ?", (machine_id,)
+        "SELECT * FROM assets WHERE machine_id = ? OR connect_id = ?",
+        (machine_id, machine_id),
     ).fetchone()
     conn.close()
     if row is None:

static/index.html

@@ -1091,7 +1091,7 @@
       </button>
     </nav>
     <div class="drawer-footer">
-      <div style="margin-bottom:6px;">Canteen Asset Tracker v3.2</div>
+      <div style="margin-bottom:6px;">Canteen Asset Tracker v3.3</div>
       <div style="font-size:11px;line-height:1.5;margin-bottom:6px;">
         <kbd>Esc</kbd> to close · <kbd>Ctrl</kbd>+<kbd>/</kbd> to search · ❓ for help
       </div>
@@ -2363,8 +2363,8 @@
     // BARCODE MODE
     // ═══════════════════════════════════════════════════════════════════════
     function _barcodeHints() {
-      // Restrict to 1D barcode formats only — much faster and more accurate
-      // than scanning all formats (QR, DataMatrix, PDF417, Aztec, etc.)
+      // All formats — 1D (Code 128, EAN, UPC, etc.) + 2D (QR, DataMatrix,
+      // PDF417, Aztec) for serial number stickers with 2D barcodes.
       const hints = new Map();
       const fmts = [
         ZXing.BarcodeFormat.CODE_128,
@@ -2376,6 +2376,10 @@
         ZXing.BarcodeFormat.CODE_93,
         ZXing.BarcodeFormat.ITF,
         ZXing.BarcodeFormat.CODABAR,
+        ZXing.BarcodeFormat.QR_CODE,
+        ZXing.BarcodeFormat.DATA_MATRIX,
+        ZXing.BarcodeFormat.PDF_417,
+        ZXing.BarcodeFormat.AZTEC,
       ];
       hints.set(ZXing.DecodeHintType.POSSIBLE_FORMATS, fmts);
       hints.set(ZXing.DecodeHintType.TRY_HARDER, true);

static/sw.js

@@ -3,7 +3,7 @@
 // Caches app shell + CDN deps. Network-first for API, cache fallback for static.
 // ═══════════════════════════════════════════════════════════════════════════
 
-const CACHE_NAME = 'canteen-v5';
+const CACHE_NAME = 'canteen-v6';
 
 // App shell — core resources needed to boot the PWA
 const APP_SHELL = [