feat(desktop): add browserPanelStore with history/loading/picker state

Per-session in-app mini-browser state: current URL, back/forward
history stack (historyIndex with forward-truncation on navigate),
loading flag, and element-picker toggle.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

desktop/src/stores/browserPanelStore.test.ts

@@ -0,0 +1,51 @@
+import { beforeEach, describe, expect, it } from 'vitest'
+import { useBrowserPanelStore } from './browserPanelStore'
+
+const reset = () => useBrowserPanelStore.setState(useBrowserPanelStore.getInitialState(), true)
+
+describe('browserPanelStore', () => {
+  beforeEach(reset)
+
+  it('opens a session at a url and records history', () => {
+    useBrowserPanelStore.getState().open('s1', 'http://localhost:5173/')
+    const s = useBrowserPanelStore.getState().bySession['s1']!
+    expect(s.url).toBe('http://localhost:5173/')
+    expect(s.isOpen).toBe(true)
+    expect(s.history).toEqual(['http://localhost:5173/'])
+    expect(s.historyIndex).toBe(0)
+    expect(s.canGoBack).toBe(false)
+  })
+
+  it('navigate pushes history and truncates forward entries', () => {
+    const st = useBrowserPanelStore.getState()
+    st.open('s1', 'http://localhost/a')
+    st.navigate('s1', 'http://localhost/b')
+    st.navigate('s1', 'http://localhost/c')
+    st.goBack('s1')
+    st.navigate('s1', 'http://localhost/d') // 截断 c
+    const s = useBrowserPanelStore.getState().bySession['s1']!
+    expect(s.history).toEqual(['http://localhost/a', 'http://localhost/b', 'http://localhost/d'])
+    expect(s.url).toBe('http://localhost/d')
+    expect(s.canGoForward).toBe(false)
+  })
+
+  it('goBack/goForward move within history without mutating it', () => {
+    const st = useBrowserPanelStore.getState()
+    st.open('s1', 'http://localhost/a')
+    st.navigate('s1', 'http://localhost/b')
+    st.goBack('s1')
+    expect(useBrowserPanelStore.getState().bySession['s1']!.url).toBe('http://localhost/a')
+    expect(useBrowserPanelStore.getState().bySession['s1']!.canGoForward).toBe(true)
+    st.goForward('s1')
+    expect(useBrowserPanelStore.getState().bySession['s1']!.url).toBe('http://localhost/b')
+  })
+
+  it('tracks loading and picker per session', () => {
+    const st = useBrowserPanelStore.getState()
+    st.open('s1', 'http://localhost/a')
+    st.setLoading('s1', true)
+    expect(useBrowserPanelStore.getState().bySession['s1']!.loading).toBe(true)
+    st.setPicker('s1', true)
+    expect(useBrowserPanelStore.getState().bySession['s1']!.pickerActive).toBe(true)
+  })
+})

desktop/src/stores/browserPanelStore.ts

@@ -0,0 +1,67 @@
+import { create } from 'zustand'
+
+export type BrowserSessionState = {
+  isOpen: boolean
+  url: string
+  history: string[]
+  historyIndex: number
+  loading: boolean
+  pickerActive: boolean
+  canGoBack: boolean
+  canGoForward: boolean
+}
+
+type BrowserPanelState = {
+  bySession: Record<string, BrowserSessionState>
+  open: (sessionId: string, url: string) => void
+  navigate: (sessionId: string, url: string) => void
+  goBack: (sessionId: string) => void
+  goForward: (sessionId: string) => void
+  setLoading: (sessionId: string, loading: boolean) => void
+  setPicker: (sessionId: string, active: boolean) => void
+  close: (sessionId: string) => void
+}
+
+const empty = (url: string): BrowserSessionState => ({
+  isOpen: true, url, history: [url], historyIndex: 0,
+  loading: false, pickerActive: false, canGoBack: false, canGoForward: false,
+})
+
+const withNav = (s: BrowserSessionState): BrowserSessionState => ({
+  ...s,
+  url: s.history[s.historyIndex]!,
+  canGoBack: s.historyIndex > 0,
+  canGoForward: s.historyIndex < s.history.length - 1,
+})
+
+export const useBrowserPanelStore = create<BrowserPanelState>((set) => ({
+  bySession: {},
+  open: (sessionId, url) => set((st) => ({
+    bySession: { ...st.bySession, [sessionId]: empty(url) },
+  })),
+  navigate: (sessionId, url) => set((st) => {
+    const cur = st.bySession[sessionId] ?? empty(url)
+    const history = [...cur.history.slice(0, cur.historyIndex + 1), url]
+    return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, isOpen: true, history, historyIndex: history.length - 1 }) } }
+  }),
+  goBack: (sessionId) => set((st) => {
+    const cur = st.bySession[sessionId]; if (!cur || cur.historyIndex <= 0) return st
+    return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, historyIndex: cur.historyIndex - 1 }) } }
+  }),
+  goForward: (sessionId) => set((st) => {
+    const cur = st.bySession[sessionId]; if (!cur || cur.historyIndex >= cur.history.length - 1) return st
+    return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, historyIndex: cur.historyIndex + 1 }) } }
+  }),
+  setLoading: (sessionId, loading) => set((st) => {
+    const cur = st.bySession[sessionId]; if (!cur) return st
+    return { bySession: { ...st.bySession, [sessionId]: { ...cur, loading } } }
+  }),
+  setPicker: (sessionId, active) => set((st) => {
+    const cur = st.bySession[sessionId]; if (!cur) return st
+    return { bySession: { ...st.bySession, [sessionId]: { ...cur, pickerActive: active } } }
+  }),
+  close: (sessionId) => set((st) => {
+    const cur = st.bySession[sessionId]; if (!cur) return st
+    return { bySession: { ...st.bySession, [sessionId]: { ...cur, isOpen: false, pickerActive: false } } }
+  }),
+}))