Bypass rexie, surface real DOM errors and harden commit batching

This release does three independent things, all motivated by the
user-visible "An IndexedDB error occured: idb error" failure reported
in surrealdb.js#571 / surrealist#1155 / indxdb#9 when calling
`db.use()` shortly after `db.connect('indxdb://...')`.

1. Wrap the underlying `idb` crate directly instead of going through
   `rexie`. The `From<rexie::Error>` conversion only ever printed
   "idb error" because `rexie::Error::IdbError` has no `{0}`
   placeholder in its `Display` impl, so the inner DOMException name
   and message were silently dropped before reaching the client. The
   new `From<idb::Error>` impl pulls the `name`/`message` out of any
   wrapped DOMException so callers see e.g. `InvalidStateError: A
   request was placed against a transaction which is currently not
   active` instead of the cryptic generic message.

2. Refactor `Transaction::commit()` to fire every buffered put and
   delete through a single read-write IDB transaction, synchronously,
   keeping only the most recently issued request handle. Only the last
   request is awaited (the same pattern `idb::ObjectStore::put_all`
   uses internally). Because no `.await` is interleaved with the
   issuing loop, the IDB transaction's pending-request queue is never
   empty during dispatch, so it cannot auto-commit prematurely. The
   previous implementation awaited each `delete()` sequentially after
   `put_all`, which the IDB spec does not guarantee will keep the
   transaction active across the wake-up microtask boundary.

3. Add a `tests/web.rs` `wasm-bindgen-test` suite covering put/get
   round-trips, mixed put+delete commits, multi-transaction sequences
   (the shape of `db.use()`), savepoint rollback, read-your-own-writes
   and conditional writes. Each test opens a freshly-named IDB
   database so the suite is parallel-safe. CI runs the suite headless
   under both Chrome and Firefox via `wasm-pack test`.

The public API is unchanged; the `rexie` dependency is dropped in
favour of `idb` directly.

Bumps the crate version to 0.13.0.

Made-with: Cursor

Author: ssttuu

.github/workflows/ci.yml

@@ -60,4 +60,29 @@ jobs:
         uses: Swatinem/rust-cache@v2
 
       - name: Run clippy
-        run: cargo clippy --target wasm32-unknown-unknown -- -D warnings
+        run: cargo clippy --all-targets --target wasm32-unknown-unknown -- -D warnings
+
+  browser-test:
+    name: Browser tests (${{ matrix.browser }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        browser: [chrome, firefox]
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: wasm32-unknown-unknown
+
+      - name: Cache cargo dependencies
+        uses: Swatinem/rust-cache@v2
+
+      - name: Install wasm-pack
+        run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+
+      - name: Run headless browser tests
+        run: wasm-pack test --headless --${{ matrix.browser }}