feat(hermes): expose '/v1/capabilities' as the 'hermes_capabilities' Tauri command

Hermes 已在 v2026.5.x 暴露 GET /v1/capabilities 给外部 UI 用作机器可读的能力描述，让前端能动态适配可用 endpoint / feature 而无需用版本号硬匹配。ClawPanel 之前完全没利用这层抽象，本 commit 加一条 Tauri 命令 + Web handler + 前端 wrapper，为后续 chat/runs/approval 等动态降级（老版 Gateway 没有的能力优雅隐藏 UI）打底。

src/lib/tauri-api.js

@@ -471,6 +471,7 @@ export const api = {
   configureHermes: (provider, apiKey, model, baseUrl) => invoke('configure_hermes', { provider, apiKey, model: model || null, baseUrl: baseUrl || null }),
   hermesGatewayAction: (action) => invoke('hermes_gateway_action', { action }),
   hermesHealthCheck: () => invoke('hermes_health_check'),
+  hermesCapabilities: () => invoke('hermes_capabilities'),
   hermesApiProxy: (method, path, body, headers) => invoke('hermes_api_proxy', { method, path, body: body || null, headers: headers || null }),
   hermesAgentRun: (input, sessionId, conversationHistory, instructions) => invoke('hermes_agent_run', { input, sessionId: sessionId || null, conversationHistory: conversationHistory || null, instructions: instructions || null }),
   hermesAgentRunStream: (input, sessionId, conversationHistory, instructions, onEvent, options) => webStreamInvoke('hermes_agent_run_stream', { input, sessionId: sessionId || null, conversationHistory: conversationHistory || null, instructions: instructions || null }, onEvent, options),