feat(clean): add Brave Service Worker and Stremio cache cleanup

[sebastianbreguel]

Summary

Two additions to `mo clean` app-specific cache cleanup, bundled per the preference stated in #643.

1. Brave Service Worker cleanup

Brave already has cache, GPU, shader, and old-version cleanup in `mo clean`. This adds the missing Service Worker cleanup — Chrome has it, Brave shares the same Chromium directory structure but was missing it.

Iterates all Brave profiles under `~/Library/Application Support/BraveSoftware/Brave-Browser/` and cleans:

• `Service Worker/CacheStorage` (via `clean_service_worker_cache`, respects protected domains)
• `Service Worker/ScriptCache/*`

2. Stremio cache cleanup

Adds two paths to `clean_video_players()` in `mo clean`:

• `~/Library/Caches/smart.stremio*/*`
• `~/Library/Application Support/stremio/stremio-server/stremio-cache/*`

Visual preview

  → Brave Service Worker, would clean 630MB, 0 protected
  → Brave Service Worker ScriptCache 217 items, 49.1MB dry
  ✓ Stremio cache, 120MB
  ✓ Stremio server cache, 2.4GB

What changed

File	Change
`lib/clean/user.sh`	Service Worker loop for Brave profiles, after Dawn cache cleanup
`lib/clean/app_caches.sh`	2 new `safe_clean` lines in `clean_video_players()`
`tests/clean_user_core.bats`	Test: Brave SW cleanup labels appear in `mo clean` output
`tests/clean_app_caches.bats`	Test: Stremio labels appear in `clean_video_players` output

Test plan

• `bats tests/clean_user_core.bats tests/clean_app_caches.bats` — 42/42 pass
• `mo clean --dry-run` — Brave Service Worker and ScriptCache appear correctly
• Stremio lines skipped cleanly when Stremio is not installed
• No regressions in existing browser/media cleanup tests

Closes #643