featmigrate from Angular to Astro static site

BREAKING CHANGE: Complete rewrite from Angular SPA to Astro

- Replace Angular 18 with Astro 5.16.7 + Tailwind CSS
- Convert all Angular components to Astro components
- Add content collections for blog with markdown support
- Setup S3 deployment with CloudFront invalidation
- Add RSS feed and sitemap generation
- Configure Prettier and Biome for code formatting
- Switch from npm to pnpm
- Remove Amplify backend (now fully static)
- Improve SEO and performance with static generation

.gitignore

@@ -1,46 +1,32 @@
-# See http://help.github.com/ignore-files/ for more about ignoring files.
+# build output
+dist/
+.output/
 
-# Compiled output
-/dist
-/tmp
-/out-tsc
-/bazel-out
+# dependencies
+node_modules/
 
-# Node
-/node_modules
-npm-debug.log
-yarn-error.log
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
 
-# IDEs and editors
-.idea/
-.project
-.classpath
-.c9/
-*.launch
-.settings/
-*.sublime-workspace
+# environment variables
+.env
+.env.production
 
-# Visual Studio Code
-.vscode/*
-!.vscode/settings.json
-!.vscode/tasks.json
-!.vscode/launch.json
-!.vscode/extensions.json
-.history/*
-
-# Miscellaneous
-/.angular/cache
-.sass-cache/
-/connect.lock
-/coverage
-/libpeerconnection.log
-testem.log
-/typings
-
-# System files
+# macOS-specific files
 .DS_Store
-Thumbs.db
+
+# jetbrains setting folders
+.idea/
+
+# vscode setting folders
+.vscode/
 
 # amplify
 .amplify
 amplifyconfiguration*
+
+# misc
+Thumbs.db