feat(web): ES-module page lifecycle and one schema field model (stage 1) (#703)

Adds a native ES-module layer to the web UI (core/boot, registry, api, facade; window.LEDMatrix as the one global), a page lifecycle that the Cache tab is converted to as the reference, text/javascript serving and revalidation for unversioned module requests, and src/plugin_system/field_model.py with a parity test against the render_field macro. Also: the cache page toggles its grey 'Not configured' style instead of only adding it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/js/README.md

@@ -51,10 +51,13 @@ server has none.
 | `unit/test_style_editor_layout_leaf_collision.js` | no | `columnsFor()` from `widgets/style-editor.js`: a layout-only leaf key still gets its own column even when its name collides with an unrelated element's style sub-field or another layout axis's sub-field |
 | `unit/test_inline_handler_escaping.js` | no | The store, saved-repository and custom-registry inline `onclick` handlers and the live `window.updateImageList` from `plugins_manager.js`: a registry id, URL or uploaded file name carrying `'`, `"` or entities adds no attributes and reaches the handler intact, and the store's View button opens only http(s) links |
 | `unit/test_store_registry_fields.js` | no | The store card's registry fields from `plugins_manager.js`: the commit that introduced the listed version (a hex SHA only, linked to that tree), the "Needs LEDMatrix X+" warning, a card from an older registry without either, and `isStorePluginInstalled` answering to `aliases` |
+| `unit/test_page_registry.js` | no | The page lifecycle in `js/core/registry.js` (a minimal DOM shim): one `init` per `data-page` root, `destroy` and an aborted `ctx.signal` when htmx swaps it away, a vetoed swap keeps it, lazy page modules, a root removed without htmx swept on the next swap |
+| `unit/test_core_modules.js` | no | `js/core/api.js` (JSON envelope, HTTP/`status: error`/network errors, abort passthrough, the #683 login redirect, same-server paths only) and `js/core/facade.js` (`window.LEDMatrix`, deprecated aliases) |
 | `unit/test_plugin_action_delegation.js` | no | The document-level card-action delegation and `handlePluginAction` from `plugins_manager.js`, run with the handler inside an IIFE as in the real file: each action is handled once, a Starlark app uninstall goes to `DELETE /starlark/apps/<id>`, and an uninstall is confirmed once |
 | `dom/test_installed_dom.js` | yes | The toolbar in a real DOM: pill/search/sort interaction, the HTMX partial re-swap, and a `getComputedStyle` check that `.filter-pill[data-active]` really matches the emitted markup |
 | `dom/test_store_dom.js` | yes | Store pagination, per-page, category, tri-state Installed button, and persistence across a re-boot, against the live registry |
 | `dom/test_no_double_fetch.js` | yes | Loads the **whole** `plugins_manager.js` and counts requests: typing in the store search must filter the cached list, not refetch `/api/v3/plugins/store/list` |
+| `dom/test_cache_page.js` | yes | The Cache tab as a page module (`js/pages/cache.js`) on the real partial: no inline script, one request per swap and per Refresh after repeated swaps, a cancelled request draws nothing, hostile keys stay text, delete/empty/error/login states |
 | `dom/test_tools_sections.js` | yes | The Tools tab's MQTT bridge and Pixlet editor sections: form prefill, the write-only password (blank means unchanged), the running-session banner and countdown, and that the editor link points at the host you loaded the page from |
 
 Point the DOM suites at a rig with a full plugin set when it matters — a dev box