chore: remove dead code (59 unused files + ~125 unused exports) (#1835)

* chore: remove dead/unreferenced files across ui, vscode

Remove 59 unused source files (components, hooks, lib utils, stores,
barrels, and orphaned vscode github modules) that are not imported by
any entry-reachable code. Also drop a stale test mock for the removed
execCommands module.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

* refactor: remove unused exported symbols (types, functions, consts, hooks)

Remove exported symbols whose identifier is referenced nowhere in the
repository (verified via repo-wide search), across ui types/contracts,
lib utilities, sync layer, stores, and components. Also drop the few
imports/private helpers orphaned by these removals.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

* refactor: remove more unused exports (desktop, shortcuts, worktree, vscode)

Continue removing repo-wide unreferenced exported functions, consts and
types across lib/desktop, shortcuts, worktreeSessionCreator, sync, and
vscode gitService, with cascading orphaned helpers/imports cleaned up.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

* chore: add dead-code cleanup tooling

* refactor: checkpoint dead-code cleanup

* refactor: remove dead-code suppressions

---------

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>
Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/sync/session-worktree-contract.ts

@@ -1,21 +1,14 @@
 import type { WorktreeMetadata } from '@/types/worktree';
 import type { SessionWorktreeAttachment } from '@/stores/types/sessionTypes';
 
-export type ResolveSessionWorktreeStateInput = {
+type ResolveSessionWorktreeStateInput = {
   sessionDirectory: string | null;
   metadata: WorktreeMetadata | null;
   cwdExists?: boolean;
   runtimeResolution?: SessionWorktreeAttachment | null;
 };
 
-export type WorktreeDirectoryValidation = {
-  valid: boolean;
-  insideWorktreeRoot: boolean;
-  resolvedWorktreeRoot: string | null;
-  resolvedCwd: string | null;
-};
-
-export type WorktreeCanonicalizationResult = {
+type WorktreeCanonicalizationResult = {
   worktreeRoot: string | null;
   cwd: string | null;
   branch: string | null;
@@ -26,7 +19,7 @@ export type WorktreeCanonicalizationResult = {
   attentionReason?: 'merge' | 'rebase' | 'cherry-pick' | 'revert' | 'bisect' | null;
 };
 
-export type SessionWorktreeCanonicalizationOptions = {
+type SessionWorktreeCanonicalizationOptions = {
   existingAttachment?: SessionWorktreeAttachment | null;
   fallbackDirectory?: string | null;
   worktreeSource?: SessionWorktreeAttachment['worktreeSource'];
@@ -39,7 +32,7 @@ const normalizePath = (value: string): string => {
   return replaced.replace(/\/+$/, '') || replaced;
 };
 
-export function isWithinWorktreeRoot(candidate: string | null, worktreeRoot: string | null): boolean {
+function isWithinWorktreeRoot(candidate: string | null, worktreeRoot: string | null): boolean {
   if (!candidate || !worktreeRoot) return false;
   const c = normalizePath(candidate);
   const r = normalizePath(worktreeRoot);