Refactor/simplify proxy logs (#585)

* refactor(proxy): simplify logging for better readability

- Delete 17 verbose debug logs from handlers, streaming, and response_processor
- Convert excessive INFO logs to DEBUG level for internal processing details
- Add 2 critical INFO logs in forwarder.rs for failover scenarios:
  - Log when switching to next provider after failure
  - Log when all providers have been exhausted
- Fix clippy uninlined_format_args warning

This reduces log noise while maintaining visibility into key user-facing decisions.

* fix: replace unsafe unwrap() calls with proper error handling

- database/dao/mcp.rs: Use map_err for serde_json serialization
- database/dao/providers.rs: Use map_err for settings_config and meta serialization
- commands/misc.rs: Use expect() for compile-time regex pattern
- services/prompt.rs: Use unwrap_or_default() for SystemTime
- deeplink/provider.rs: Replace unwrap() with is_none_or pattern for Option checks

Reduces potential panic points from 26 to 1 (static regex init, safe).

* refactor(proxy): simplify verbose logging output

- Remove response JSON full output logging in response_processor
- Remove per-request INFO logs in provider_router (failover status, provider selection)
- Change model mapping log from INFO to DEBUG
- Change usage logging failure from INFO to WARN
- Remove redundant debug logs for circuit breaker operations

Reduces log noise significantly while preserving important warnings and errors.

* feat(proxy): add structured log codes for i18n support

Add error code system to proxy module logs for multi-language support:

- CB-001~006: Circuit breaker state transitions and triggers
- SRV-001~004: Proxy server lifecycle events
- FWD-001~002: Request forwarding and failover
- FO-001~005: Failover switch operations
- USG-001~002: Usage logging errors

Log format: [CODE] Chinese message
Frontend/log tools can map codes to any language.

New file: src/proxy/log_codes.rs - centralized code definitions

* chore: bump version to 3.9.1

* style: format code with prettier and rustfmt

* fix(ui): allow number inputs to be fully cleared before saving

- Convert numeric state to string type for controlled inputs
- Use isNaN() check instead of || fallback to allow 0 values
- Apply fix to ProxyPanel, CircuitBreakerConfigPanel,
  AutoFailoverConfigPanel, and ModelTestConfigPanel

* feat(pricing): support @ separator in model name matching

- Refactor model name cleaning into chained method calls
- Add @ to - replacement (e.g., gpt-5.2-codex@low → gpt-5.2-codex-low)
- Add test case for @ separator matching

* fix(proxy): improve validation and error handling in proxy config panels

- Add StopTimeout/StopFailed error types for proper stop() error reporting
- Replace silent clamp with validation-and-block in config panels
- Add listenAddress format validation in ProxyPanel
- Use log_codes constants instead of hardcoded strings
- Use once_cell::Lazy for regex precompilation

* fix(proxy): harden error handling and input validation

- Handle RwLock poisoning in settings.rs with unwrap_or_else
- Add fallback for dirs::home_dir() in config modules
- Normalize localhost to 127.0.0.1 in ProxyPanel
- Format IPv6 addresses with brackets for valid URLs
- Strict port validation with pure digit regex
- Treat NaN as validation failure in config panels
- Log warning on cost_multiplier parse failure
- Align timeoutSeconds range to [0, 300] across all panels

src/i18n/locales/en.json

@@ -1107,7 +1107,12 @@
       "toast": {
         "saved": "Proxy configuration saved",
         "saveFailed": "Save failed: {{error}}"
-      }
+      },
+      "invalidPort": "Invalid port, please enter a number between 1024-65535",
+      "invalidAddress": "Invalid address, please enter a valid IP address (e.g. 127.0.0.1) or localhost",
+      "configSaved": "Proxy configuration saved",
+      "configSaveFailed": "Failed to save configuration",
+      "restartRequired": "Restart proxy service for address or port changes to take effect"
     },
     "switchFailed": "Switch failed: {{error}}",
     "failover": {
@@ -1134,6 +1139,7 @@
       "info": "When the failover queue has multiple providers, the system will try them in priority order when requests fail. When a provider reaches the consecutive failure threshold, the circuit breaker will open and skip it temporarily.",
       "configSaved": "Auto failover config saved",
       "configSaveFailed": "Failed to save",
+      "validationFailed": "The following fields are out of valid range: {{fields}}",
       "retrySettings": "Retry & Timeout Settings",
       "failureThreshold": "Failure Threshold",
       "failureThresholdHint": "Open circuit breaker after this many consecutive failures (recommended: 3-10)",
@@ -1185,6 +1191,16 @@
     "streamingIdle": "Streaming Idle Timeout",
     "nonStreaming": "Non-Streaming Timeout"
   },
+  "circuitBreaker": {
+    "failureThreshold": "Failure Threshold",
+    "successThreshold": "Success Threshold",
+    "timeoutSeconds": "Timeout (seconds)",
+    "errorRateThreshold": "Error Rate Threshold",
+    "minRequests": "Min Requests",
+    "validationFailed": "The following fields are out of valid range: {{fields}}",
+    "configSaved": "Circuit breaker config saved",
+    "saveFailed": "Failed to save"
+  },
   "universalProvider": {
     "title": "Universal Provider",
     "description": "Universal providers manage Claude, Codex, and Gemini configurations simultaneously. Changes are automatically synced to all enabled apps.",

src/i18n/locales/zh.json

@@ -1107,7 +1107,12 @@
       "toast": {
         "saved": "代理配置已保存",
         "saveFailed": "保存失败: {{error}}"
-      }
+      },
+      "invalidPort": "端口无效，请输入 1024-65535 之间的数字",
+      "invalidAddress": "地址无效，请输入有效的 IP 地址（如 127.0.0.1）或 localhost",
+      "configSaved": "代理配置已保存",
+      "configSaveFailed": "保存配置失败",
+      "restartRequired": "修改地址或端口后需要重启代理服务才能生效"
     },
     "switchFailed": "切换失败: {{error}}",
     "failover": {
@@ -1134,6 +1139,7 @@
       "info": "当故障转移队列中配置了多个供应商时，系统会在请求失败时按优先级顺序依次尝试。当某个供应商连续失败达到阈值时，熔断器会打开并在一段时间内跳过该供应商。",
       "configSaved": "自动故障转移配置已保存",
       "configSaveFailed": "保存失败",
+      "validationFailed": "以下字段超出有效范围: {{fields}}",
       "retrySettings": "重试与超时设置",
       "failureThreshold": "失败阈值",
       "failureThresholdHint": "连续失败多少次后打开熔断器（建议: 3-10）",
@@ -1185,6 +1191,16 @@
     "streamingIdle": "流式静默超时",
     "nonStreaming": "非流式超时"
   },
+  "circuitBreaker": {
+    "failureThreshold": "失败阈值",
+    "successThreshold": "成功阈值",
+    "timeoutSeconds": "超时时间",
+    "errorRateThreshold": "错误率阈值",
+    "minRequests": "最小请求数",
+    "validationFailed": "以下字段超出有效范围: {{fields}}",
+    "configSaved": "熔断器配置已保存",
+    "saveFailed": "保存失败"
+  },
   "universalProvider": {
     "title": "统一供应商",
     "description": "统一供应商可以同时管理 Claude、Codex 和 Gemini 的配置。修改后会自动同步到所有启用的应用。",