docs(cli): document worktree rm branch cleanup (#16167)

Document that Git worktree removal may also delete the checked-out local branch, while clarifying that --force does not force branch deletion and that Orca retains branches whose changes cannot be proven merged.

src/cli/help.ts

@@ -547,7 +547,8 @@ export function formatFlagHelp(flag: string): string {
     'element-index': '--element-index <n>   Element index from get-app-state',
     title: '--title <text>         Custom title for the terminal tab (omit to reset)',
     enter: '--enter                Append Enter after sending text',
-    force: '--force                Force worktree removal when supported',
+    force:
+      '--force                Force worktree removal when supported; does not force branch deletion',
     focus: '--focus                Reveal the created terminal session in Orca',
     for: '--for exit|tui-idle    Wait condition to satisfy',
     'from-element-index': '--from-element-index <n> Source element index from get-app-state',

src/cli/specs/core.ts

@@ -170,7 +170,10 @@ export const CORE_COMMAND_SPECS: CommandSpec[] = [
     summary: 'Remove a worktree from Orca and git',
     usage: 'orca worktree rm --worktree <selector> [--force] [--run-hooks] [--json]',
     allowedFlags: [...GLOBAL_FLAGS, 'worktree', 'force', 'run-hooks'],
-    notes: ['Repo-defined orca.yaml archive hooks are skipped unless --run-hooks is passed.']
+    notes: [
+      'Repo-defined orca.yaml archive hooks are skipped unless --run-hooks is passed.',
+      'For Git worktrees, removal also attempts to delete the checked-out local branch, with or without --force. Orca retains branches it knows predated the worktree and any branch whose changes it cannot prove are already merged.'
+    ]
   },
   {
     path: ['worktree', 'ps'],