[dmccoystephenson]

What changes

The browser page used to show "Loading env-lib-cpp on Strata…" while the engine downloaded. It now loads behind the Strata web kit's loading shell (strata-loader.js, from Strata's web/kit/, vendored at 901e6c9 in strata/web/strata-kit/ with PIN, SHA256SUMS, LICENSE and update.sh, the same way gardener vendors the kit):

• Backdrop: the /play trailer's first frame, blurred, from https://danielstephenson.dev/trailers/.
• Progress: byte-accurate, with the size, and role=progressbar. The loader streams the .wasm and hands its bytes to the engine, so nothing downloads twice.
• Fallback: when the live view can't run (no WebGL 2, the renderer fails, the engine stops, a lost WebGL context does not come back), the trailer plays with the reason in words and a "More games" link. Under prefers-reduced-motion, the still is shown instead of the clip.
• Slow devices: a device drawing under 12 frames a second over 8 s is offered the clip without losing the live view. This check is skipped in automated browsers and ?bench runs.

How it is wired

• strata/web/strata-boot.js bridges this classic (non-MODULARIZE) build to the loader. emcc's {{{ SCRIPT }}} tag sits inert in <template id="strata-glue">. The bridge starts the glue, and the engine waits in Module.instantiateWasm for the loader's bytes.
• strata/web/strata_page.cmake runs after each link. It puts the loader and the bridge inline in the page, so the site is still the same four files and the workflow is unchanged. It also stamps the download's size on the template, because the arcade compresses on the fly and sends no Content-Length.
• The files live under strata/web/ (strata-kit/, strata-boot.js, strata_page.cmake), next to the page.
• The #loading box now only shows in-page errors. window.envlib, ?world= and ?bench are unchanged.
• The smoke test now checks that the shell finishes. It also checks that without WebGL 2 the shell says why and downloads nothing of the engine.

Checked locally

The build used emsdk 6.0.11 and Strata c2d7ee4. It was served by a local server that gzips on the fly with no Content-Length, as the arcade does.

• strata/web/smoke/smoke.cjs passed on desktop and phone (iPhone 13), including the new shell checks.
• strata/web/smoke/bench.cjs ?bench=3 passed on desktop and phone.
• ctest (wasm under Node) passed: 1/1.
• arcade-watch's strata check, run locally on desktop, passed: wasm instantiated, WebGL 2, frames and draws advancing, envlib.status().tick advancing, the canvas not blank, and the shell gone.
• Screenshots were taken at 390×844 of the loading state, a throttled download part way, and the no-WebGL 2 fallback with and without reduced motion.

Drafted by Claude on behalf of Daniel Stephenson.

🤖 Generated with Claude Code

https://claude.ai/code/session_01LYNeuo5Ry76i84tz6WXQSE

[dmccoystephenson]

Review of PR #65 (adopted by a Gardener tend run; no prior review was recorded on this PR).

Rubric:

• Scope: PASS — every file serves the loading shell: the vendored kit (strata/web/strata-kit/), the bridge (strata-boot.js), the post-link page step (strata_page.cmake + strata/CMakeLists.txt), the page (shell.html), the smoke test, and docs/STRATA.md. No src/ or Makefile changes.
• Tests-new: PASS — strata/web/smoke/smoke.cjs now asserts the shell reaches done and that, with WebGL 2 stubbed out, the shell states the reason and no envlib-strata.(wasm|js) request is made.
• Tests-fix: not applicable — no bug fix in scope.
• Vendored integrity: PASS — sha256sum of strata-loader.js and LICENSE matches SHA256SUMS (7da2a43f…, 8e3fc647…). The only network call in the loader is the same-origin .wasm fetch (strata-loader.js:213); no innerHTML/eval use was found, and reason text goes through textContent.
• Docs: PASS — docs/STRATA.md gains "The loading shell" section matching the wiring; README.md's class table is unaffected (no library classes changed).
• Do-not-auto-merge paths: PASS — no .github/workflows/*, security/, or Makefile change; no file deletes more than 50 lines.
• CI anchor: PASS — "Library tests (make + CMake)", "Strata frontend (build, tests, headless render)", and "Web build and smoke test (headless Chromium)" are all green on the PR head; the branch already contains master (merge state CLEAN).

Non-blocking notes:

• strata/web/shell.html:153 — onRendererFailed still writes to #loading, which is now display: none, so that text is never seen; the loader's fallback carries the message instead. It is harmless but could be dropped later.
• strata/web/strata_page.cmake:37 — the -DDATA= option is accepted but strata/CMakeLists.txt never passes it (this build has no --preload-file package). It reads as forward compatibility rather than a defect.
• strata/web/strata-boot.js:117 — the instantiateWasm closure references resolveFactory, declared with let further down; this is safe because it only runs after start() returns, but hoisting the declaration would read more clearly.

Verdict: ready to merge.

This review was drafted during a Gardener session (https://github.com/Stephenson-Software/gardener).

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drafted by Claude on behalf of Daniel Stephenson