feat: add Bedrock request optimizer (PRE-SEND thinking + cache injection) (#1301)

* feat: add Bedrock request optimizer (PRE-SEND thinking + cache injection)

Add a PRE-SEND request optimizer that enhances Bedrock API requests
before forwarding, complementing the existing POST-ERROR rectifier system.

New modules:
- thinking_optimizer: 3-path model detection (adaptive/legacy/skip)
  - Opus 4.6/Sonnet 4.6: adaptive thinking + effort max + 1M context beta
  - Legacy models: inject extended thinking with max budget
  - Haiku: skip (no modification)
- cache_injector: auto-inject cache_control breakpoints (max 4)
  - Injects at tools/system/assistant message positions
  - TTL upgrade for existing breakpoints (5m → 1h)

Gate: only activates for Bedrock providers (CLAUDE_CODE_USE_BEDROCK=1)
Config: stored in SQLite settings table, default OFF, user opt-in
UI: new Optimizer section in RectifierConfigPanel with 3 toggles + TTL

18 unit tests covering all paths. Verified against live Bedrock API.

* chore: remove docs/plans directory

* fix: address code review findings for Bedrock request optimizer

P0 fixes:
- Replace hardcoded Chinese with i18n t() calls in optimizer panel,
  add translation keys to zh/en/ja locale files
- Fix u64 underflow: max_tokens - 1 → max_tokens.saturating_sub(1)
- Move optimizer from before retry loop to per-provider with body
  cloning, preventing Bedrock fields leaking to non-Bedrock providers

P1 fixes:
- Replace .map() side-effect pattern with idiomatic if-let (clippy)
- Fix module alphabetical ordering in mod.rs
- Add cache_ttl whitelist validation in set_optimizer_config
- Remove #[allow(unused_assignments)] and dead budget decrement

---------

Co-authored-by: Keith (via OpenClaw) <keithyt06@users.noreply.github.com>
Co-authored-by: Jason <farion1231@gmail.com>

src-tauri/src/database/dao/settings.rs

@@ -187,6 +187,29 @@ impl Database {
         self.set_setting("rectifier_config", &json)
     }
 
+    // --- 优化器配置 ---
+
+    /// 获取优化器配置
+    ///
+    /// 返回优化器配置，如果不存在则返回默认值（默认关闭）
+    pub fn get_optimizer_config(&self) -> Result<crate::proxy::types::OptimizerConfig, AppError> {
+        match self.get_setting("optimizer_config")? {
+            Some(json) => serde_json::from_str(&json)
+                .map_err(|e| AppError::Database(format!("解析优化器配置失败: {e}"))),
+            None => Ok(crate::proxy::types::OptimizerConfig::default()),
+        }
+    }
+
+    /// 更新优化器配置
+    pub fn set_optimizer_config(
+        &self,
+        config: &crate::proxy::types::OptimizerConfig,
+    ) -> Result<(), AppError> {
+        let json = serde_json::to_string(config)
+            .map_err(|e| AppError::Database(format!("序列化优化器配置失败: {e}")))?;
+        self.set_setting("optimizer_config", &json)
+    }
+
     // --- 日志配置 ---
 
     /// 获取日志配置