feat: vscode extension (#59)

* feat: add initial VS Code extension plan and implementation tasks

* feat(vscode): added initial version of an Openchamber VSCode extension

* feat(vscode): enhance VS Code extension with theme integration and session management

* feat(vscode): implement connection status handling and overlay in VSCode layout

* feat: move extension to secondary sidebar

* chore: upgrade @opencode-ai/sdk to 1.0.150

* vscode: editor bridge, file picker, click-to-open in tool parts

* vscode: layout session lifecycle, theme sync, typography overrides

* ui: compact mode for vscode, model search, autocomplete width fixes

* perf: scroll force flag, raf placeholder, git polling backoff

* ui: tool output styling, markdown code block fix, gitignore

* refactor: update typography handling for VSCode runtime, remove unused styles

* docs: update README with VS Code extension details and add extension image

* docs: update changelog with new features and performance improvements

packages/vscode/webview/hooks/useNavigation.ts

@@ -0,0 +1,17 @@
+import { create } from 'zustand';
+
+export type ViewType = 'sessions' | 'chat';
+
+interface NavigationState {
+  currentView: ViewType;
+  navigateTo: (view: ViewType) => void;
+  goToChat: () => void;
+  goToSessions: () => void;
+}
+
+export const useNavigation = create<NavigationState>((set) => ({
+  currentView: 'sessions',
+  navigateTo: (view) => set({ currentView: view }),
+  goToChat: () => set({ currentView: 'chat' }),
+  goToSessions: () => set({ currentView: 'sessions' }),
+}));