Fix WASM release tests and publish v0.1.28 - #8

Summary

• replace stale IndexedDB test metadata with complete BlockMetadataPersist records carrying real checksums
• preserve caller-supplied metadata versions and omit the commit-marker write in crash-simulation persistence, allowing recovery to detect interrupted commits
• record start, success, failure, duration, and block counts for the public asynchronous WASM sync path
• run the exact release-mode Chrome WASM suite in regular CI so release-only compile/runtime failures cannot recur
• bump Cargo, npm, generated package metadata, and the mobile lockfile to 0.1.28

Root causes

The v0.1.27 Release workflow compiled a broader WASM test matrix than regular CI. Four test call sites still passed the old (block_id, version) scalar form after persist_to_indexeddb_event_based moved to (block_id, BlockMetadataPersist).

Once that matrix ran in regular CI, its crash test exposed that the marker-less simulation helper internally forced metadata versions to zero and wrote a zero commit marker. Recovery therefore saw no version ahead of the marker. The corrected path retains retries while preserving the supplied next-version metadata and intentionally omitting the marker write.

The same suite also showed that the public asynchronous WASM sync() path bypassed observability bookkeeping, leaving sync_count at zero after a successful durable sync. It now records sync start, success/failure, duration, and block count.

Release recovery

crates.io 0.1.27 was published before its WASM job failed; npm and the GitHub Release were skipped. This PR does not rewrite or move v0.1.27. Exact merged main will be tagged v0.1.28 so crates.io, npm, and GitHub Release align on the corrected release.

Validation

CI run 30240107197 passed all six jobs:

• formatting and clippy
• native Rust tests
• tracked version consistency
• complete release-mode WASM tests in headless Chrome
• Hybrid browser storage and benchmark Playwright coverage
• production PWA storage Playwright coverage