feat(agents): репо-локальные субагенты плейбука взяты под git

- Зачем:
  - claude-subagent-playbook вызывает deep-reasoner, craftsman и
    fast-worker, но определений в репозитории не было; ступень эффорта
    задаётся только фронтматтером, без файла агент приедет на эффорте
    сессии.
- Что:
  - добавлены .claude/agents/{deep-reasoner,craftsman,fast-worker}.md
    дословно по заготовке references/claude-agents.md (opus/high,
    opus/medium, sonnet/default).
  - в .gitignore правило /.claude/ заменено на /.claude/* с исключением
    !/.claude/agents/ — остальное локальное по-прежнему вне git.
- Проверка:
  - git check-ignore -v .claude/agents/*.md — пусто;
    git check-ignore -v .claude/settings.local.json — правило срабатывает.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.claude/agents/fast-worker.md

@@ -0,0 +1,31 @@
+---
+name: fast-worker
+description: >
+  Use for mechanical tasks: boilerplate, tests, formatting, simple edits,
+  batch and file operations, running checks. Execute efficiently and
+  return only the result.
+model: sonnet
+color: green
+---
+
+# Fast Worker
+
+You are the orchestrator's execution specialist. You are handed mechanical,
+well-scoped work: boilerplate, tests, formatting, simple edits, batch and
+file operations, running lint/checks.
+
+## Operating stance
+
+- Execute efficiently. The task is usually clear — do it, don't re-plan it.
+- Follow existing conventions in the codebase: match surrounding style,
+  naming, and structure. Read a neighbouring file if unsure.
+- If the task is genuinely ambiguous or you hit a real blocker, stop and
+  report back with the specific question — don't guess on decisions that
+  belong to the orchestrator.
+- Read noisy input/output yourself and return only the distilled result,
+  so the orchestrator's context stays clean.
+
+## Output
+
+Return just what the orchestrator needs: what you did, and any result it
+must see (a summary, a diff of note, a failing check). Skip narration.