[bobleer]

Summary

Move packaged frontend file resolution off the WebView callback thread, load the appearance and visual-skin ZIP readers only when importing a package, and add an opt-out for native window material when comparing compositing cost.

Packaged hashed assets use content ETags with mandatory revalidation. Legacy customizations share these URLs, so long-lived immutable caching would serve stale scripts after preview, activation or rollback. Editable assets, bootstrap pages and failures retain no-store.

The related embedded Relay path now grants immutable caching only to successful hashed build assets (and their 304 responses). Unversioned files, HTML and missing chunks no longer receive a one-year cache lifetime.

Type and Areas

Type: performance improvement and regression prevention.

Areas: desktop/Tauri, Web UI appearance and visual-skin imports.

Motivation / Impact

Lazy chunk loads no longer perform filesystem reads and canonicalization on the WebView callback thread. Archive dependencies leave the initial loading path. OPENBITFUN_NATIVE_WINDOW_MATERIAL=0 selects the existing opaque fallback on macOS and Windows for controlled performance comparisons; normal behavior is unchanged.

Verification

All local checks passed on macOS:

• pnpm run check:web and pnpm run build:web: type-check, appearance/theme gates, generated API bindings, Monaco assets and WebKit compatibility.
• 107 focused frontend tests: AppearancePackageParser, ThemeTokenAppearanceAdapter, visual-skin archive/parser/runtime regressions, and startupPerformanceContract.
• cargo test --locked -p openbitfun-desktop --no-default-features --lib frontend_: 37 tests, including legacy state, upgrades, controller-local/Peer admission and cache behavior. The 31 frontend_workbench tests were rerun after the final response-header correction.
• cargo test --locked -p openbitfun-desktop --no-default-features --lib embedded_relay_host: 3 tests, including real loopback HTTP for mutable assets, hashed assets, 304s and 404s.
• cargo test --locked -p openbitfun-desktop --no-default-features --lib window_material::tests: 4 tests, with both default settings and OPENBITFUN_NATIVE_WINDOW_MATERIAL=0; 2 appearance::startup_appearance_tests also passed.
• cargo check --locked -p openbitfun-desktop --no-default-features --lib and cargo build --locked -p openbitfun-desktop --features devtools.
• node tests/e2e/scripts/run-creation-runtime.mjs, with default material, OPENBITFUN_NATIVE_WINDOW_MATERIAL=0, and --suspended-paint: real packaged WebView loading, custom frontend activation, reload persistence and MiniApp create/open/render/update/delete all passed on the final build.
• An additional native WebView probe checked GET/ETag/304/HEAD and a missing asset. The 2,137,345-byte entry chunk returned 304 with an empty body and the correct representation length; HEAD preserved that length and the 404 stayed no-store.
• pnpm run fmt:rs, git diff --check, and node scripts/check-git-object-sizes.mjs --base upstream/main --head HEAD.

Production output confirms that JSZip and zip.js are dynamically imported chunks: 257,577 bytes total (101,679 bytes gzip). This measures deferred bundle bytes, not end-to-end startup latency.

Reviewer Notes

AI-assisted; testing level: fully tested for the stated local macOS scope. Cross-platform CI passed on commit 8bb93e31a: 11 checks succeeded and 2 impact-selected jobs were skipped. The CI workflow is successful. No persisted shape or wire protocol changes. Remote Control's embedded static HTTP path is covered by loopback fixtures; Peer/controller admission is covered by local fixtures. No live Remote Workspace, Remote Control device, Peer Device Mode or Detached Dispatch scenario was exercised. Native Windows/Linux rendering and end-to-end performance timing remain outside local verification.

Checklist

• This PR is focused and does not include secrets, temporary prompts, generated scratch files, or unrelated artifacts.
• Relevant verification is recorded above, or skipped checks are explained.
• User-facing strings, docs, and locales are updated where applicable.