fix: use network-first for navigation to prevent stale HTML/MIME errors

[krusty-agent]

Problem

The text/html is not a valid JavaScript MIME type error keeps happening even after PR #23.

Root Cause Analysis

PR #23 correctly stopped caching hashed assets, BUT the cached index.html still references old asset hashes:

1. User visits site → SW caches / (index.html with <script src="/assets/index-abc123.js">)
2. New deploy happens → new index.html references index-xyz456.js
3. User revisits → SW serves cached old HTML
4. Browser tries to load index-abc123.js → 404 → SPA fallback returns HTML
5. Browser fails: 'text/html' is not a valid JavaScript MIME type

Solution

Network-first for navigation requests - ensures users always get fresh HTML.

Changes to service-worker.ts:

• Navigation requests now use network-first strategy
• Only fall back to cache when offline
• Cache version bumped to lisa-v3 to clear old caches
• Improved asset hash detection regex

Changes to sw-registration.ts:

• Stale asset detection: Listens for script errors and dynamic import failures
• Auto-clears all caches and reloads when MIME errors detected
• updateViaCache: 'none' forces SW update checks on every page load
• Periodic SW update checks every 5 minutes
• Auto-reload on controllerchange (when new SW activates)

Testing

• Build succeeds ✅
• SW correctly serves fresh HTML on navigation
• Hashed assets bypass SW entirely (browser caching via immutable headers)
• Existing users with bad caches will auto-recover on MIME error

Breaking Changes

None. Users with old SWs will either:

1. Get new SW on next visit (controllerchange → auto-reload)
2. Hit MIME error → auto-clear and reload
3. Work normally once new SW is active

Fixes the persistent MIME type error issue.