feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

mobile/README.md

@@ -0,0 +1,100 @@
+# Buzz Mobile
+
+Flutter mobile client for Buzz.
+
+## Setup
+
+```bash
+cd mobile
+flutter pub get
+```
+
+## Run
+
+```bash
+# From repo root (recommended — starts Docker, relay, and simulator):
+just mobile-dev
+
+# Direct (requires services and relay already running):
+cd mobile && flutter run
+```
+
+### Worktree-aware debug identity
+
+Debug builds produced from a git worktree get a unique app identifier keyed
+to the **worktree directory name** (`com.buzz.buzzMobile.<slug>` on iOS,
+`xyz.block.buzz.mobile.<slug>` on Android) plus a display-only branch label
+in the app name (`Buzz (my-branch)`, or a short SHA when the worktree is
+detached). Because the identifier follows the directory rather than the
+branch, one worktree keeps exactly one installed app — and its login state —
+across branch switches, and builds from multiple worktrees install side by
+side, mirroring the desktop dev experience. Release and profile builds
+always keep the production identity and name.
+
+`just mobile-dev` and `just mobile-build-android` apply this automatically by
+running `scripts/mobile-worktree-overrides.sh`, which writes two gitignored
+files:
+
+- `mobile/ios/Flutter/WorktreeOverrides.xcconfig` (included by Debug builds
+  only; a developer's `AppOverrides.xcconfig` is included after it, so
+  app-specific overrides like a personal `BUNDLE_IDENTIFIER` for device
+  signing always win)
+- `mobile/android/worktree.properties` (read by the debug build type only)
+
+For direct Xcode / Android Studio / `flutter run` development, run
+`./scripts/mobile-worktree-overrides.sh` from the repo root once per branch
+switch to refresh the display label (the install identity never changes);
+the persisted files are then picked up by any subsequent build. In the main
+checkout the script is a no-op that removes stale override files, restoring
+the plain `Buzz` identity.
+
+To remove leftover worktree-suffixed installs from booted iOS simulators and
+connected Android emulators, run `just mobile-clean` (add `--dry-run` via
+`./scripts/mobile-worktree-clean.sh --dry-run` to preview). Production
+installs are never touched.
+
+## Checks
+
+```bash
+dart format --output=none --set-exit-if-changed .
+flutter analyze
+flutter test
+```
+
+Or from the repo root: `just mobile-check` and `just mobile-test`.
+
+## Android release signing
+
+Android release builds fail unless all upload-key inputs are supplied through the
+environment:
+
+- `BUZZ_ANDROID_UPLOAD_KEYSTORE_PATH`: path to a CI-vended keystore file
+- `BUZZ_ANDROID_UPLOAD_KEYSTORE_PASSWORD`
+- `BUZZ_ANDROID_UPLOAD_KEY_ALIAS`
+- `BUZZ_ANDROID_UPLOAD_KEY_PASSWORD`
+
+The keystore path must be absolute, and the keystore must remain outside the
+repository. Development and debug builds do not require these variables.
+
+Release pipelines that sign through the central APK Signer service instead of
+a local upload keystore must set `BUZZ_ANDROID_RELEASE_SIGNING=external`. That
+mode produces an unsigned release bundle and refuses to run if any
+`BUZZ_ANDROID_UPLOAD_*` value is also set.
+
+## Architecture
+
+```
+lib/
+├── main.dart              # Entry point, Riverpod bootstrap
+├── app.dart               # MaterialApp with theme
+├── shared/
+│   └── theme/             # Catppuccin light/dark, spacing tokens, extensions
+└── features/
+    └── home/              # Placeholder home surface
+```
+
+- **State management:** Riverpod + Hooks (`HookConsumerWidget`)
+- **Theme:** Catppuccin Latte (light) / Macchiato (dark) — matches desktop
+- **Spacing:** `Grid` tokens for consistent spacing
+- **Linting:** `flutter_lints` + `riverpod_lint` via `custom_lint`
+- **Feature isolation:** No cross-feature imports except `shared/`