feat(march-madness): add NCAA tournament plugin and round logos (#263)

* feat: add March Madness plugin and tournament round logos

New dedicated March Madness plugin with scrolling tournament ticker:
- Fetches NCAA tournament data from ESPN scoreboard API
- Shows seeded matchups with team logos, live scores, and round separators
- Highlights upsets (higher seed beating lower seed) in gold
- Auto-enables during tournament window (March 10 - April 10)
- Configurable for NCAAM and NCAAW tournaments
- Vegas mode support via get_vegas_content()

Tournament round logo assets:
- MARCH_MADNESS.png, ROUND_64.png, ROUND_32.png
- SWEET_16.png, ELITE_8.png, FINAL_4.png, CHAMPIONSHIP.png

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(store): prevent bulk-update from stalling on bundled/in-repo plugins

Three related bugs caused the bulk plugin update to stall at 3/19:

1. Bundled plugins (e.g. starlark-apps, shipped with LEDMatrix rather
   than the plugin registry) had no metadata file, so update_plugin()
   returned False → API returned 500 → frontend queue halted.
   Fix: check for .plugin_metadata.json with install_type=bundled and
   return True immediately (these plugins update with LEDMatrix itself).

2. git config --get remote.origin.url (without --local) walked up the
   directory tree and found the parent LEDMatrix repo's remote URL for
   plugins that live inside plugin-repos/. This caused the store manager
   to attempt a 60-second git clone of the wrong repo for every update.
   Fix: use --local to scope the lookup to the plugin directory only.

3. hello-world manifest.json had a trailing comma causing JSON parse
   errors on every plugin discovery cycle (fixed on devpi directly).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(march-madness): address PR #263 code review findings

- Replace self.is_enabled with BasePlugin.self.enabled in update(),
  display(), and supports_dynamic_duration() so runtime toggles work
- Support quarter-based period labels for NCAAW (Q1..Q4 vs H1..H2),
  detected via league key or status_detail content
- Use live refresh interval (60s) for cache max_age during live games
  instead of hardcoded 300s
- Narrow broad except in _load_round_logos to (OSError, ValueError)
  with a fallback except Exception using logger.exception for traces
- Remove unused `situation` local variable from _parse_event()
- Add numpy>=1.24.0 to requirements.txt (imported but was missing)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Chuck <chuck@example.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

plugin-repos/march-madness/requirements.txt

@@ -0,0 +1,4 @@
+requests>=2.28.0
+Pillow>=9.0.0
+pytz>=2022.1
+numpy>=1.24.0