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/core/src/store.ts

@@ -556,7 +556,7 @@ export class TaskStore extends EventEmitter<TaskStoreEvents> {
       const id = this.db.transaction(() => {
         const row = this.db.prepare("SELECT nextId, settings FROM config WHERE id = 1").get() as any;
         const settings = fromJson<Settings>(row.settings);
-        const prefix = settings?.taskPrefix || "FN";
+        const prefix = settings?.taskPrefix || "KB";
         const nextId = row.nextId || 1;
         const taskId = `${prefix}-${String(nextId).padStart(3, "0")}`;
         this.db.prepare("UPDATE config SET nextId = ? WHERE id = 1").run(nextId + 1);
@@ -1284,7 +1284,7 @@ export class TaskStore extends EventEmitter<TaskStoreEvents> {
         );
       }
 
-      const branch = `fusion/${id.toLowerCase()}`;
+      const branch = `kb/${id.toLowerCase()}`;
       const worktreePath = task.worktree;
       const result: MergeResult = {
         task,

packages/core/src/types.ts

@@ -580,8 +580,8 @@ export interface ProjectSettings {
    *  - "task-title": Use a slugified version of the task title (e.g., fix-login-bug)
    *  Default: "random". */
   worktreeNaming?: "random" | "task-id" | "task-title";
-  /** Prefix for generated task IDs (e.g. `"FN"` produces `FN-001`).
-   *  Defaults to `"FN"`. Only affects new tasks — existing tasks retain
+  /** Prefix for generated task IDs (e.g. `"KB"` produces `KB-001`).
+   *  Defaults to `"KB"`. Only affects new tasks — existing tasks retain
    *  their original IDs. */
   taskPrefix?: string;
   /** When true, merge commit messages include the task ID as the conventional