Feature/global proxy (#596)

* 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

* feat(proxy): add global proxy settings support

Add ability to configure a global HTTP/HTTPS proxy for all outbound
requests including provider API calls, speed tests, and stream checks.

* 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

* feat(proxy): add local proxy auto-scan and fix hot-reload

- Add scan_local_proxies command to detect common proxy ports
- Fix SkillService not using updated proxy after hot-reload
- Move global proxy settings to advanced tab
- Add error handling for scan failures

* fix(proxy): allow localhost input in proxy address field

* fix(proxy): restore request timeout and fix proxy hot-reload issues

- Add URL scheme validation in build_client (http/https/socks5/socks5h)
- Restore per-request timeout for speedtest, stream_check, usage_script, forwarder
- Fix set_global_proxy_url to validate before persisting to DB
- Mask proxy credentials in all log outputs
- Fix forwarder hot-reload by fetching client on each request

* style: format code with prettier

* fix(proxy): improve global proxy stability and error handling

- Fix RwLock silent failures with explicit error propagation
- Handle init() duplicate calls gracefully with warning log
- Align fallback client config with build_client settings
- Make scan_local_proxies async to avoid UI blocking
- Add mixed mode support for Clash 7890 port (http+socks5)
- Use multiple test targets for better proxy connectivity test
- Clear invalid proxy config on init failure
- Restore timeout constraints in usage_script
- Fix mask_url output for URLs without port
- Add structured error codes [GP-001 to GP-009]

* feat(proxy): add username/password authentication support

- Add separate username and password input fields
- Implement password visibility toggle with eye icon
- Add clear button to reset all proxy fields
- Auto-extract auth info from saved URL and merge on save
- Update i18n translations (zh/en/ja)

* fix(proxy): fix double encoding issue in proxy auth and add debug logs

- Remove encodeURIComponent in mergeAuth() since URL object's
  username/password setters already do percent-encoding automatically
- Add GP-010 debug log for database read operations
- Add GP-011 debug log to track incoming URL info (length, has_auth)
- Fix username.trim() in fallback branch for consistent behavior

src-tauri/src/proxy/forwarder.rs

@@ -12,10 +12,9 @@ use super::{
     ProxyError,
 };
 use crate::{app_config::AppType, provider::Provider};
-use reqwest::{Client, Response};
+use reqwest::Response;
 use serde_json::Value;
 use std::sync::Arc;
-use std::time::Duration;
 use tokio::sync::RwLock;
 
 /// Headers 黑名单 - 不透传到上游的 Headers
@@ -81,8 +80,6 @@ pub struct ForwardError {
 }
 
 pub struct RequestForwarder {
-    client: Option<Client>,
-    client_init_error: Option<String>,
     /// 共享的 ProviderRouter（持有熔断器状态）
     router: Arc<ProviderRouter>,
     status: Arc<RwLock<ProxyStatus>>,
@@ -93,6 +90,8 @@ pub struct RequestForwarder {
     app_handle: Option<tauri::AppHandle>,
     /// 请求开始时的"当前供应商 ID"（用于判断是否需要同步 UI/托盘）
     current_provider_id_at_start: String,
+    /// 非流式请求超时（秒）
+    non_streaming_timeout: std::time::Duration,
 }
 
 impl RequestForwarder {
@@ -108,51 +107,14 @@ impl RequestForwarder {
         _streaming_first_byte_timeout: u64,
         _streaming_idle_timeout: u64,
     ) -> Self {
-        // 全局超时设置为 1800 秒（30 分钟），确保业务层超时配置能正常工作
-        // 参考 Claude Code Hub 的 undici 全局超时设计
-        const GLOBAL_TIMEOUT_SECS: u64 = 1800;
-
-        let timeout_secs = if non_streaming_timeout > 0 {
-            non_streaming_timeout
-        } else {
-            GLOBAL_TIMEOUT_SECS
-        };
-
-        // 注意：这里不能用 expect/unwrap。
-        // release 配置为 panic=abort，一旦 build 失败会导致整个应用闪退。
-        // 常见原因：用户环境变量里存在不合法/不支持的代理（HTTP(S)_PROXY/ALL_PROXY 等）。
-        let (client, client_init_error) = match Client::builder()
-            .timeout(Duration::from_secs(timeout_secs))
-            .build()
-        {
-            Ok(client) => (Some(client), None),
-            Err(e) => {
-                // 降级：忽略系统/环境代理，避免因代理配置问题导致整个应用崩溃
-                match Client::builder()
-                    .timeout(Duration::from_secs(timeout_secs))
-                    .no_proxy()
-                    .build()
-                {
-                    Ok(client) => (Some(client), Some(e.to_string())),
-                    Err(fallback_err) => (
-                        None,
-                        Some(format!(
-                            "Failed to create HTTP client: {e}; no_proxy fallback failed: {fallback_err}"
-                        )),
-                    ),
-                }
-            }
-        };
-
         Self {
-            client,
-            client_init_error,
             router,
             status,
             current_providers,
             failover_manager,
             app_handle,
             current_provider_id_at_start,
+            non_streaming_timeout: std::time::Duration::from_secs(non_streaming_timeout),
         }
     }
 
@@ -416,16 +378,17 @@ impl RequestForwarder {
         // 默认使用空白名单，过滤所有 _ 前缀字段
         let filtered_body = filter_private_params_with_whitelist(request_body, &[]);
 
-        // 构建请求
-        let client = self.client.as_ref().ok_or_else(|| {
-            ProxyError::ForwardFailed(
-                self.client_init_error
-                    .clone()
-                    .unwrap_or_else(|| "HTTP client is not initialized".to_string()),
-            )
-        })?;
+        // 每次请求时获取最新的全局 HTTP 客户端（支持热更新代理配置）
+        let client = super::http_client::get();
         let mut request = client.post(&url);
 
+        // 只有当 timeout > 0 时才设置请求超时
+        // Duration::ZERO 在 reqwest 中表示"立刻超时"而不是"禁用超时"
+        // 故障转移关闭时会传入 0，此时应该使用 client 的默认超时（600秒）
+        if !self.non_streaming_timeout.is_zero() {
+            request = request.timeout(self.non_streaming_timeout);
+        }
+
         // 过滤黑名单 Headers，保护隐私并避免冲突
         for (key, value) in headers {
             if HEADER_BLACKLIST