build(meezi_app): Flutter Koja now builds for web (mirror + platform gen + fixes)

Connectivity fixed: pub.dev/googleapis are 403 under sanctions, so PUB_HOSTED_URL
+ FLUTTER_STORAGE_BASE_URL now point at the reachable Flutter mirror
(pub.flutter-io.cn / storage.flutter-io.cn) — set persistently on the build machine.

- `flutter create --platforms=android,web --org ir.meezi` generated android/ + web/
  (#33). `flutter build web` succeeds; `flutter analyze` errors all cleared.
- pubspec: intl ^0.19.0 → ^0.20.2 (SDK pins 0.20.2 via flutter_localizations).
- Fixed 3 pre-existing compile errors (app had never been built):
  * attendance: JalaliFormatter.yyyyMMdd() removed → build the date from year/month/day.
  * qr_scan: dropped a call to a non-existent CartNotifier.setTable (table context is
    already set via tableContextProvider just above).
  * widget_test: default counter test referenced MyApp → minimal MeeziApp smoke test.
- discover_screen: drop redundant foundation import; value → initialValue (non-deprecated).

Verified: flutter build web ✓. (Android packaging still needs a Gradle/Maven mirror.)

mobile/meezi_app/.gitignore

@@ -0,0 +1,45 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.build/
+.buildlog/
+.history
+.svn/
+.swiftpm/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins-dependencies
+.pub-cache/
+.pub/
+/build/
+/coverage/
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release