## Title

`sprimo-tauri` runtime shows `TypeError: W.fromURL is not a function`; sprite renderer fails to initialize.

## Severity

P1

## Environment

- OS: Windows
- App: `sprimo-tauri` frontend/runtime path
- Reported on: 2026-02-13
- Evidence screenshot: `issues/screenshots/issue2.png`

## Summary

At runtime, the Tauri UI loads but Pixi sprite rendering fails with:

- `TypeError: W.fromURL is not a function`

This breaks sprite presentation and leaves the UI in an error state.

## Reproduction Steps

1. Build UI assets and start the Tauri app (`just build-tauri-ui`, `just run-tauri`).
2. Open the Tauri window and wait for sprite pack initialization.
3. Observe the debug panel error and missing pet rendering.

## Expected Result

- Pixi atlas texture loads successfully from `atlas_data_url`.
- Pet sprite renders and animates.
- No renderer initialization error in UI.

## Actual Result

- Renderer initialization fails with `TypeError: W.fromURL is not a function`.
- Sprite is not rendered.

## Root Cause Analysis

- `frontend/tauri-ui/src/renderer/pixi_pet.ts` used `BaseTexture.fromURL(...)`.
- In the current Pixi package/runtime composition, that API path is unavailable at runtime
  (minified symbol resolves to `W.fromURL`, which is undefined).
- Result: atlas load throws before a valid sprite texture can be applied.
- Follow-up finding: Tauri can run previously embedded frontend assets if Rust build is not
  re-triggered after UI-only changes, which can make old errors appear even after source fixes.
- After stale-build issue was resolved (`ui build: issue2-fix3` visible), a second runtime defect
  became clear:
  - `event.listen not allowed` due missing Tauri capability permissions for event listen/unlisten.
  - sprite pack still rendered with magenta matte because tauri path lacked chroma-key conversion.

## Fix Plan

1. Replace `BaseTexture.fromURL` usage with Pixi assets loader (`@pixi/assets` + `Assets.load`).
2. Ensure sprite texture is assigned immediately after renderer creation (first frame visible).
3. Harden React lifecycle cleanup to avoid stale listeners/renderer leaks.
4. Re-run tauri/runtime QA checks and keep issue at `Fix Implemented` until strict gate evidence is complete.

## Implementation Notes

Implemented:

1. `frontend/tauri-ui/package.json`
- Added `@pixi/assets` dependency.

2. `frontend/tauri-ui/src/renderer/pixi_pet.ts`
- Switched atlas loading to `Assets.load<Texture>(pack.atlas_data_url)`.
- Reused `texture.baseTexture` for frame slicing.
- Applied initial frame texture in constructor so sprite appears immediately.
- Added explicit renderer/sprite/ticker disposal path.

3. `frontend/tauri-ui/src/main.tsx`
- Added mount guards to prevent state updates after unmount.
- Added deterministic cleanup (`unlisten` + renderer `dispose()`).

4. `crates/sprimo-tauri/build.rs`
- Added `cargo:rerun-if-changed` directives for tauri config and frontend UI paths so
  frontend/dist updates re-trigger asset embedding in `cargo run -p sprimo-tauri`.

5. `frontend/tauri-ui/src/renderer/pixi_pet.ts`
- Replaced `Assets.load` path with direct `Image` + `BaseTexture.from(image)` loading to avoid
  any runtime `*.fromURL` dependency in atlas initialization.

6. `frontend/tauri-ui/src/main.tsx`
- Added visible UI build marker (`issue2-fix3`) to detect stale embedded frontend artifacts.

7. `crates/sprimo-tauri/capabilities/default.json`
- Added default capability with:
  - `core:default`
  - `core:event:allow-listen`
  - `core:event:allow-unlisten`

8. `frontend/tauri-ui/src/renderer/pixi_pet.ts`
- Added tauri-side chroma-key conversion for atlas data URL:
  - draw atlas to canvas
  - convert near-`#FF00FF` pixels to alpha 0
  - create Pixi base texture from converted canvas

## Verification

### Commands Run

- [x] `cargo check -p sprimo-tauri`
- [x] `cargo check -p sprimo-runtime-core`
- [x] `just build-tauri-ui`
- [x] `just run-tauri` (smoke attempt; command is long-running and timed out under automation)
- [x] `just qa-validate`

### Visual Checklist

- [x] Before screenshot(s): `issues/screenshots/issue2.png`
- [x] After screenshot(s): `issues/screenshots/issue2-after-fix3-2026-02-13-094131.png`

### Runtime Contract Checklist

- [ ] `current_state` invoke returns structured payload
- [ ] `load_active_sprite_pack` invoke returns manifest/atlas payload
- [ ] `runtime:snapshot` event observed after runtime command changes

### API Checklist

- [ ] `GET /v1/health`
- [ ] `GET /v1/state` auth behavior
- [ ] `POST /v1/command`
- [ ] `POST /v1/commands`

### Result

- Current Status: `Fix Implemented`
- Notes: build/check/qa validation passed; manual runtime visual verification still required.

## Status History

- `2026-02-13 13:20` - reporter - `Reported` - runtime screenshot captured with `TypeError: W.fromURL is not a function`.
- `2026-02-13 13:35` - codex - `Triaged` - localized failure to Pixi atlas loader path.
- `2026-02-13 13:55` - codex - `In Progress` - replaced loader API and hardened renderer lifecycle.
- `2026-02-13 14:05` - codex - `Fix Implemented` - patch completed, verification checklist queued.
- `2026-02-13 14:20` - codex - `Fix Implemented` - checks passed (`cargo check`, UI build, QA validation); smoke launch attempted.
- `2026-02-13 14:35` - codex - `Fix Implemented` - added build-script change tracking for frontend assets to prevent stale embedded UI.
- `2026-02-13 14:55` - codex - `In Progress` - removed all runtime `fromURL` usage from renderer atlas loading path.
- `2026-02-13 15:05` - codex - `In Progress` - added explicit UI build marker to detect stale executable/frontend embedding.
- `2026-02-13 15:20` - reporter - `In Progress` - provided `issue2-after-fix3` screenshot; stale-build issue resolved, permission + chroma-key defects observed.
- `2026-02-13 15:35` - codex - `Fix Implemented` - added tauri capability permission file and tauri-side chroma-key conversion.

## Closure

- Current Status: `Fix Implemented`
- Close Date:
- Owner:
- Linked PR/commit: