feat(KB-640): add role editing UI and restore KB task prefix

- Add inline role editing to AgentListModal with clickable role icons
- Add handleRoleChange and handleRoleKeyDown handlers for role updates
- Persist view toggle (board/list) with localStorage alongside role editing
- Restore task prefix from FN back to KB for generated task IDs
- Restore branch naming from fusion/ back to kb/ for task branches
- Update branch name references in executor, merger, scheduler, and CLI
- Add touch gesture detection support to TaskCard component
- Update worktree grouping labels to use KB prefix

packages/engine/src/worktree-pool.ts

@@ -111,8 +111,8 @@ export class WorktreePool {
    * 3. `git checkout -B <branchName> <startPoint>` — create/reset branch from start point
    *
    * @param worktreePath — Absolute path to the recycled worktree
-   * @param branchName — Branch name for the new task (e.g., `fusion/fn-042`)
-   * @param startPoint — Git ref to branch from (e.g., `fusion/fn-041`). Defaults to `main`.
+   * @param branchName — Branch name for the new task (e.g., `kb/kb-042`)
+   * @param startPoint — Git ref to branch from (e.g., `kb/kb-041`). Defaults to `main`.
    */
   prepareForTask(worktreePath: string, branchName: string, startPoint?: string): void {
     // Clean tracked modifications