feat: add integrate commits to parental branch section and wired UI

Introduce IntegrateCommitsSection to plan and apply commits from source to target branch
Wire the integration panel into GitView so users can run integrate flow from the current worktree

packages/ui/src/lib/openchamberConfig.ts

@@ -11,6 +11,7 @@ import { isVSCodeRuntime } from './desktop';
 type ProjectRef = { id: string; path: string };
 
 const CONFIG_FILENAME = 'openchamber.json';
+// LEGACY_PROJECT_CONFIG: legacy per-project config root inside repo.
 const LEGACY_CONFIG_DIR = '.openchamber';
 const USER_CONFIG_DIR_SEGMENTS = ['.config', 'openchamber'];
 const USER_PROJECTS_DIR_SEGMENTS = ['.config', 'openchamber', 'projects'];