feat: add provider login flow (#4)

## Summary

- replace the former three-provider model with two pre-login choices:
  - **ABox**: authenticate through the vendor ABSDK on the current local network
  - **Local experience**: establish a production simulation session without credentials, network access, or ABSDK calls
- remove the compatible-backend product/server scope and safely ignore legacy persisted compatible-provider values
- bind one process-wide `AbsdkBridge` for ABox session, socket, temperature/humidity, and infrared operations
- add production `:runtime:simulation` implementations and route device operations by the active provider
- retain provider-scoped username preferences, Keystore-encrypted automatic-login credentials, token recovery, logout, and session isolation
- add regression coverage for authentication gating, profile/session alignment, provider switching cleanup, routing, and simulation behavior
- align requirement, plan, architecture, and protocol documentation with LAN ABSDK access

## Verification

```text
./gradlew check testDebugUnitTest test
BUILD SUCCESSFUL (220 actionable tasks)

./gradlew :android:app:assembleDebug :android:app:assembleRelease
BUILD SUCCESSFUL (217 actionable tasks)

./gradlew :android:app:compileDebugAndroidTestKotlin
BUILD SUCCESSFUL

git diff --check
passed
```

Emulator smoke validation:

- provider selection displays ABox and Local experience only
- Local experience enters the authenticated route without credentials
- Local experience also enters while emulator Wi-Fi/data are disabled
- Local Sign out and Switch provider return to provider selection
- ABox opens the credential form; empty submission stays on login with the required-fields error

## Known constraints and accepted risks

- The vendor JAR uses cleartext HTTP and hardcodes `a-box.com.cn`; Debug and Release intentionally share the same ABox capability under the approved no-Release-exception decision. `@CleartextAbsdkTransport`, `usesCleartextTraffic`, and the architecture/protocol documents explicitly record this risk. This does not provide confidentiality or integrity.
- Real authenticated ABox and read-only hardware smoke validation is deferred because the gateway is currently unavailable locally. This PR does not claim that current-environment validation completed.
- The mapping from the vendor JAR's hardcoded hostname to the LAN gateway remains an external network/deployment prerequisite. The ABSDK JAR and bridge path remain identical to the previously hardware-validated `feat/moler-infrared-control` branch.
- `FakeDeviceCatalog` remains a temporary debug-only placeholder until the device-catalog module provides the production ABox catalog. ABox catalog requests are not routed to Local experience simulation.

Reviewed-on: #4
Co-authored-by: KremeCN <3265494849@qq.com>

android/app/src/main/res/values-zh-rCN/strings.xml

@@ -1,8 +1,27 @@
 <resources>
     <string name="app_name">ABox Manager</string>
-    <string name="foundation_title">工程基础已就绪</string>
-    <string name="foundation_description">公共领域接口和本地开发提供方已经可用。</string>
-    <string name="continue_action">继续</string>
-    <string name="placeholder_title">功能模块可以开始开发</string>
-    <string name="placeholder_description">设备、红外和情景页面将由对应模块负责人实现。</string>
+    <string name="provider_selection_title">选择提供方</string>
+    <string name="provider_selection_description">选择当前配置的连接方式。不同提供方之间的会话、凭据和本地数据相互隔离。</string>
+    <string name="provider_abox_name">ABox</string>
+    <string name="provider_abox_description">通过 ABSDK 连接当前局域网中的 ABox 智能家居网关。</string>
+    <string name="provider_local_name">本地体验</string>
+    <string name="provider_local_description">无需网络，通过本地模拟设备体验应用。</string>
+    <string name="login_title">登录 %1$s</string>
+    <string name="login_provider_context">当前提供方：%1$s</string>
+    <string name="login_back_to_providers">返回提供方选择</string>
+    <string name="login_username">用户名</string>
+    <string name="login_password">密码</string>
+    <string name="login_remember_username">记住用户名</string>
+    <string name="login_auto_login">自动登录</string>
+    <string name="login_error_required">请输入用户名和密码。</string>
+    <string name="login_error_invalid_credentials">用户名或密码不正确。</string>
+    <string name="login_error_network">网络不可用，请重试。</string>
+    <string name="login_error_session_expired">会话已失效，请重新登录。</string>
+    <string name="login_error_preferences">无法加载已保存的登录设置。</string>
+    <string name="login_error_failed">登录失败，请重试。</string>
+    <string name="action_login">登录</string>
+    <string name="action_logout">退出登录</string>
+    <string name="action_switch_provider">切换提供方</string>
+    <string name="authenticated_title">已连接到 %1$s</string>
+    <string name="authenticated_description">登录后入口已经就绪，设备导航将由对应模块负责人接入。</string>
 </resources>