feat: add searxng web-search provider, openrouter cost balance UI, offline scripts; update source-launch and docs

docs/capability-seams.zh.md

@@ -166,6 +166,7 @@ flowchart LR
   pkg_web["web"]
   svc_web["ctx.web<br/>Web access provider registry"]
   pkg_web_search_exa["web-search-exa"]
+  pkg_web_search_searxng["web-search-searxng"]
   pkg_web_search_perplexity["web-search-perplexity"]
   pkg_web_search_deepseek["web-search-deepseek"]
   pkg_web_fetch_http["web-fetch-http"]
@@ -192,6 +193,9 @@ flowchart LR
   pkg_lsp_local["lsp-local"]
   pkg_tool_lsp["tool-lsp"]
   svc_apiProxy["ctx.apiProxy<br/>Host API dispatch"]
+  pkg_openrouter_usage["openrouter-usage"]
+  svc_openRouterUsage["ctx.openRouterUsage<br/>OpenRouter usage and balance gateway"]
+  pkg_ui_openrouter_usage["ui-openrouter-usage"]
   pkg_cordis_host_runner["cordis-host-runner"]
   svc_dynamicCordisRunner["ctx.dynamicCordisRunner<br/>Dynamic Cordis package host runner"]
   svc_cordisInspect["ctx.cordisInspect<br/>Dynamic Cordis inspect registry"]
@@ -237,6 +241,7 @@ flowchart LR
   pkg_lsp_local --> svc_lsp
   pkg_message_feedback --> svc_messageFeedback
   pkg_modules --> svc_clientModules
+  pkg_openrouter_usage --> svc_openRouterUsage
   pkg_permission_presets --> svc_permissionPresets
   pkg_plan_mode --> svc_planMode
   pkg_pwsh_local --> svc_shell
@@ -292,6 +297,7 @@ flowchart LR
   pkg_web_search_deepseek --> svc_web
   pkg_web_search_exa --> svc_web
   pkg_web_search_perplexity --> svc_web
+  pkg_web_search_searxng --> svc_web
   pkg_webserver --> svc_webServer
   pkg_workflow --> svc_workflowEngine
   pkg_workflow_worker_thread --> svc_workflowEngine
@@ -330,6 +336,7 @@ flowchart LR
   svc_llm --> pkg_agent_loop
   svc_llm --> pkg_compaction_basic
   svc_lsp --> pkg_tool_lsp
+  svc_openRouterUsage --> pkg_ui_openrouter_usage
   svc_sandbox --> pkg_bash_sandbox
   svc_sandbox --> pkg_terminal_bash
   svc_sandboxPolicy --> pkg_bash_sandbox
@@ -459,7 +466,7 @@ flowchart LR
 | `ctx.compaction` | `seam` | [`compaction`](../packages/compaction/compaction) | [`compaction-basic`](../packages/compaction/compaction-basic) | [`compaction-basic`](../packages/compaction/compaction-basic) | - | 基础后端消费步骤后的压力事件和请求错误恢复事件；不存在面向模型的压缩工具。 |
 | `ctx.subagents` | `seam` | [`subagent`](../packages/subagent/subagent) | [`subagent-spawn-in-process`](../packages/subagent/subagent-spawn-in-process), [`subagent-fork-in-process`](../packages/subagent/subagent-fork-in-process), [`subagent-acp`](../packages/subagent/subagent-acp), [`subagent-codex`](../packages/subagent/subagent-codex), [`subagent-claude-code`](../packages/subagent/subagent-claude-code), [`subagent-dsh-sdk`](../packages/subagent/subagent-dsh-sdk) | [`tool-subagent`](../packages/subagent/tool-subagent), [`tool-subagent-control`](../packages/subagent/tool-subagent-control), [`tool-ralph`](../packages/workflow/tool-ralph) | - | 提供方实现传输；该服务还负责可选的、基于 Activation 的延续编排，tool-subagent 选择一次性或可延续委派，tool-subagent-control 传递后续消息，而 tool-ralph 要求一条全新的结构化输出路由。 |
 | `ctx.jobs` | `seam` | [`jobs`](../packages/jobs/jobs) | [`jobs-local`](../packages/jobs/jobs-local) | [`tool-bash`](../packages/shell/tool-bash), [`tool-terminal`](../packages/terminal/tool-terminal), [`tool-subagent`](../packages/subagent/tool-subagent), [`tool-jobs`](../packages/jobs/tool-jobs) | - | 生产方（后台 bash、PTY 发送和 subagent 委派）登记正在运行的工作；tool-jobs 是面向模型的控制器，用于读取、列出和终止这些工作；jobs-local 是进程本地注册表。 |
-| `ctx.web` | `seam` | [`web`](../packages/web/web) | [`web-search-exa`](../packages/web/web-search-exa), [`web-search-perplexity`](../packages/web/web-search-perplexity), [`web-search-deepseek`](../packages/web/web-search-deepseek), [`web-fetch-http`](../packages/web/web-fetch-http) | [`tool-web`](../packages/web/tool-web) | - | 搜索和抓取提供方注册到同一个 ctx.web seam；tool-web 负责稳定的面向模型名称。 |
+| `ctx.web` | `seam` | [`web`](../packages/web/web) | [`web-search-exa`](../packages/web/web-search-exa), [`web-search-searxng`](../packages/web/web-search-searxng), [`web-search-perplexity`](../packages/web/web-search-perplexity), [`web-search-deepseek`](../packages/web/web-search-deepseek), [`web-fetch-http`](../packages/web/web-fetch-http) | [`tool-web`](../packages/web/tool-web) | - | 搜索和抓取提供方注册到同一个 ctx.web seam；tool-web 负责稳定的面向模型名称。 |
 | `ctx.spillStore` | `seam` | [`spill`](../packages/spill/spill) | [`spill-local`](../packages/spill/spill-local) | [`spill-policy`](../packages/spill/spill-policy) | - | 后端保存过大的工具文本，并返回面向模型的定位信息和取回提示；spill-policy 是 tools/post-execute 消费方，负责决定何时 spill。 |
 | `ctx.directoryPicker` | `seam` | `directory-picker` | `directory-picker-native`, `directory-picker-browse` | `apiproxy` | - | 带判别标记的交互能力：原生后端在 Host 显示设备上打开一个操作系统选择器，浏览后端为应用内浏览器提供列表与创建原语；双端后端通过其浏览器侧填充 ui-workspace 目录流程的 slot（不通过协议发布）。 |
 | `ctx.webServer` | `core` | `webserver` | - | `connection`, `modules`, `hmr` | - | 普通的 node:http 载体：具名路由注册表、索引转换 tap，以及静态 dist 回退；Web 传输插件注册自己的路由。 |
@@ -467,6 +474,7 @@ flowchart LR
 | `ctx.workflowEngine` | `seam` | [`workflow`](../packages/workflow/workflow) | [`workflow-worker-thread`](../packages/workflow/workflow-worker-thread) | [`tool-workflow`](../packages/workflow/tool-workflow), [`tool-ralph`](../packages/workflow/tool-ralph) | - | 每个上下文使用一个引擎，与 bash 相同，且没有具名提供方注册表；通用工作流与固定 Ralph 消费方启动运行，其中的 agent() 调用通过 ctx.subagents 扇出。 |
 | `ctx.lsp` | `seam` | [`lsp`](../packages/lsp/lsp) | `lsp-local` | [`tool-lsp`](../packages/lsp/tool-lsp) | - | 提供方注册与选择，加上恰好四种操作的标准化查询执行；该 seam 不提供协议逃生口，后端必须转换为标准化请求和结果。 |
 | `ctx.apiProxy` | `core` | `apiproxy` | - | `connection` | - | 与传输无关的 Host 网关接口：它分派浏览器 API 调用，每条打开的 Host 流自行订阅转发事件，而不是由广播方法向其推送。 |
+| `ctx.openRouterUsage` | `core` | [`openrouter-usage`](../packages/llm/openrouter-usage) | - | `ui-openrouter-usage` | - | Host 网关折叠 token 用量投影与实时余额快照；Web UI 客户端通过其 remote 命名空间经线路访问同一服务。 |
 | `ctx.dynamicCordisRunner` | `core` | [`cordis-host-runner`](../packages/extensions/cordis-host-runner) | - | [`tool-cordis`](../packages/extensions/tool-cordis) | - | 拥有内存定义注册表、Host 半的 vm 沙箱和 request-run 往返流程；浏览器页面通过其 Remote 命名空间在线访问同一服务。 |
 | `ctx.cordisInspect` | `core` | [`cordis-host-runner`](../packages/extensions/cordis-host-runner) | - | [`tool-cordis`](../packages/extensions/tool-cordis) | - | 注册 Host inspect 提供方、镜像 Client 提供方 manifest，并通过动态 Cordis 传输路由 Client 查询。 |