feat(ui): add desktop git sidebar + terminal dock and improve in-app PR workflow (#362)

* feat: add unified dropdown with services content in header

* feat: add right Git sidebar with resizable panel

* feat: implement responsive panel auto-toggle and terminal rehydration

- Auto-close the right sidebar when width is below a threshold and auto-open it when space permits
- Auto-close the bottom terminal when height is below a threshold and auto-open it when enough space
- Apply a dedicated rehydrated streaming configuration for terminal sessions to optimize reconnect behavior

* feat: enhance PR view with status caching and annotations

* feat(ui): enable chat dispatch in PullRequestSection

* feat(TerminalView): adjust layout

* feat: refine chat input layout and text selection menu

* fix(ui): show empty state in GitView when no changes

* feat(git): update PR actions styling and create PR button

packages/vscode/webview/api/github.ts

@@ -12,6 +12,7 @@ import type {
   GitHubPullRequestMergeResult,
   GitHubPullRequestReadyInput,
   GitHubPullRequestReadyResult,
+  GitHubPullRequestUpdateInput,
   GitHubPullRequestStatus,
   GitHubDeviceFlowComplete,
   GitHubDeviceFlowStart,
@@ -34,6 +35,8 @@ export const createVSCodeGitHubAPI = (): GitHubAPI => ({
     sendBridgeMessage<GitHubPullRequestStatus>('api:github/pr:status', { directory, branch }),
   prCreate: async (payload: GitHubPullRequestCreateInput) =>
     sendBridgeMessage<GitHubPullRequest>('api:github/pr:create', payload),
+  prUpdate: async (payload: GitHubPullRequestUpdateInput) =>
+    sendBridgeMessage<GitHubPullRequest>('api:github/pr:update', payload),
   prMerge: async (payload: GitHubPullRequestMergeInput) =>
     sendBridgeMessage<GitHubPullRequestMergeResult>('api:github/pr:merge', payload),
   prReady: async (payload: GitHubPullRequestReadyInput) =>