优化页面交互并增强 Provider 配置能力

- 表单下拉框不再用 label 包裹，改为 div + aria-label，避免点击后
  下拉面板瞬间关闭
- Provider 卡片新增「从上游获取模型」和「修改」入口，支持编辑
  base URL、API Key 与 api_mode，凭据写入对应的环境变量
- 服务端抽出 provider-model-discovery 统一不同 api_mode 的模型发现，
  旧的 custom_providers 与新的 providers 字典结构都能正确更新
- Agent Bridge 改为后台启动，HTTP 接口在 Python 运行时就绪前即可用；
  worker 连接被拒时按类型重试，不重放可能已产生副作用的请求
- 断线重连后恢复 profiles、models 与会话列表，健康检查改为自调度
  的 setTimeout，离线时 2 秒后重试
- 批量删除确认文案改用 Popconfirm content，避免变成侧栏触发器文本

tests/server/agent-bridge-worker-readiness.test.ts

@@ -0,0 +1,83 @@
+import { createServer, type Server } from 'net'
+import { afterEach, describe, expect, it } from 'vitest'
+import { AgentBridgeClient } from '../../packages/server/src/services/hermes/agent-bridge/client'
+
+const servers: Server[] = []
+afterEach(async () => {
+  await Promise.all(servers.splice(0).map(server => new Promise<void>(resolve => server.close(() => resolve()))))
+})
+
+async function broker(reply: (request: Record<string, unknown>) => Record<string, unknown>, retryMs = 1000) {
+  const server = createServer(socket => {
+    let buffer = ''
+    socket.on('data', data => {
+      buffer += data.toString()
+      if (!buffer.includes('\n')) return
+      socket.end(`${JSON.stringify(reply(JSON.parse(buffer)))}\n`)
+    })
+  })
+  servers.push(server)
+  await new Promise<void>(resolve => server.listen(0, '127.0.0.1', resolve))
+  const address = server.address()
+  if (!address || typeof address === 'string') throw new Error('Missing test broker address')
+  return new AgentBridgeClient({ endpoint: `tcp://127.0.0.1:${address.port}`, connectRetryMs: retryMs, timeoutMs: 1000 })
+}
+
+const refused = { ok: false, error: '[Errno 111] Connection refused', error_type: 'ConnectionRefusedError' }
+
+describe('Agent Bridge worker readiness', () => {
+  it('waits for a cold worker and for a worker restarting after idle without losing the message', async () => {
+    const requests: Record<string, unknown>[] = []
+    let ready = false
+    const client = await broker(request => {
+      requests.push(request)
+      if (!ready) {
+        ready = true
+        return refused
+      }
+      return { ok: true, run_id: `run-${requests.length}`, session_id: request.session_id }
+    })
+    await expect(client.chat('session', 'first message', [], undefined, 'default')).resolves.toMatchObject({ ok: true })
+    ready = false
+    await expect(client.chat('session', 'after idle', [{ role: 'user', content: 'first message' }])).resolves.toMatchObject({ ok: true })
+    expect(requests).toHaveLength(4)
+    expect(requests[0]).toEqual(requests[1])
+    expect(requests[2]).toEqual(requests[3])
+  })
+
+  it('retries a worker socket that has not been created yet', async () => {
+    let attempts = 0
+    const client = await broker(() => ++attempts === 1
+      ? { ok: false, error: '[Errno 2] No such file or directory', error_type: 'FileNotFoundError' }
+      : { ok: true })
+    await expect(client.request({ action: 'worker_ping', profile: 'default' })).resolves.toEqual({ ok: true })
+    expect(attempts).toBe(2)
+  })
+
+  it.each([
+    { ok: false, error: '[Errno 111] Connection refused' },
+    { ok: false, error: '[Errno 111] Connection refused', error_type: 'RuntimeError' },
+    { ok: false, error: 'worker closed without a response', error_type: 'RuntimeError' },
+    { ok: false, error: 'timed out', error_type: 'TimeoutError' },
+  ])('does not replay ambiguous failures: $error_type $error', async response => {
+    let attempts = 0
+    const client = await broker(() => { attempts++; return response })
+    await expect(client.chat('session', 'message')).rejects.toThrow(response.error)
+    expect(attempts).toBe(1)
+  })
+
+  it('stops retrying persistent worker refusal within the configured budget', async () => {
+    let attempts = 0
+    const client = await broker(() => { attempts++; return refused }, 150)
+    await expect(client.chat('session', 'message')).rejects.toThrow('Connection refused')
+    expect(attempts).toBeGreaterThan(1)
+    expect(attempts).toBeLessThanOrEqual(4)
+  })
+
+  it('honors disabled retries', async () => {
+    let attempts = 0
+    const client = await broker(() => { attempts++; return refused }, 0)
+    await expect(client.chat('session', 'message')).rejects.toThrow('Connection refused')
+    expect(attempts).toBe(1)
+  })
+})