v0.7.3: 重构 Provider 层 + 计算层隔离 + Cleaner/NoMemory 架构

- 删除 OpenAIProvider/OllamaProvider 死代码，LuaAdaptedProvider 独存
- DisableThinking 从 ExtraBody 移到 CompletionRequest 顶层字段
- ContextWindow 从 Provider 签名移到 BaseConfig/ModelContextWindow() 统管
- 确认 CleanText 仅做基本空白 trim，QQ 模板剥离归插件 Cleaner
- Cleaner/NoMemory 仅作用于向量计算和 jieba 分词层，原文不变
- context.ContextEvent/Doc.Content 始终保存原文
- 删除 nlp/download.go 死代码
- media.go: context.Background() -> a.ctx 级联
- clawhubadapter: HTTP 超时
- cut.go: 跨平台 mod cache 路径 (GOMODCACHE->GOPATH->HomeDir)
- bridge_e2e_test: 移除未用 runtime import
- lua 适配器: disable_thinking 传参

internal/lua/adapters/anthropic.lua

@@ -7,7 +7,6 @@ adapter.headers = {
     ["anthropic-version"] = "2023-06-01"
 }
 
--- Anthropic Messages API: { model, messages[], max_tokens, system, stream }
 function adapter.transform_request(raw_body)
     local ok, req = pcall(json.decode, raw_body)
     if not ok then return raw_body end
@@ -28,6 +27,11 @@ function adapter.transform_request(raw_body)
         messages = msgs,
         stream = req.stream or false,
     }
+
+    if not req.disable_thinking then
+        anthropic_req.thinking = { type = "enabled", budget_tokens = 4096 }
+    end
+
     if system ~= "" then
         anthropic_req.system = system
     end