feat: Replace foliate-js submodule with npm git dependency

Migrate from git submodule to npm package management for better
developer experience and simplified deployment.
Changes:
- Add @bookhoard/foliate-js from GitHub fork
(john-okeefe/foliate-js#bookhoard-panel-detection)
- Update vite alias to point to node_modules instead of vendor
- Delete .gitmodules (no submodules tracked)
- Remove scripts/setup-git-hooks.sh (no longer needed)
- Delete web/vendor/foliate-js/ submodule directory
- Remove sc-commit git alias (submodule-specific)
Benefits:
- Standard npm workflow (npm install / npm update)
- No authentication issues for end users (public GitHub)
- Simpler deployment (npm ci in containers)
- foliate-js protected in node_modules (AI won't rewrite)
- Independent project management
- Cleaner git history
Technical details:
- Import remains unchanged: import "foliate-js/view.js"
- Vite alias maps "foliate-js" to "/node_modules/@bookhoard/foliate-js"
- Build verified working (reader.js includes foliate-js)
- Package installed from git branch: bookhoard-panel-detection

vite.config.ts

@@ -3,7 +3,7 @@ export default defineConfig({
   resolve: {
     alias: {
       "@": "/web/src",
-      "foliate-js": "/web/vendor/foliate-js",
+      "foliate-js": "/node_modules/@bookhoard/foliate-js", // Updated path
     },
   },
   base: "/static/",