feat(skills): добавлен скилл session-state-handoff

- Зачем:
  - после прерывания или сжатия контекста нужна возможность продолжить работу в новой сессии.
- Что:
  - создан agents/.agents/skills/session-state-handoff/SKILL.md.
  - скилл формирует документ-передачу и список скиллов для следующей сессии.
- Проверка:
  - вызвать скилл session-state-handoff и проверить созданный документ.

agents/.agents/skills/session-state-handoff/SKILL.md

@@ -0,0 +1,16 @@
+---
+name: session-state-handoff
+description: Keep current session state and possibility of resume after compaction or in fresh session.
+argument-hint: "How to keep current work after interruption?"
+disable-model-invocation: false
+---
+
+Write a handoff document summarising the current conversation so a fresh agent can continue the work. Save to the temporary directory of the user's OS or where is prescribed in AGENTS.md or other project config.
+
+Include a "suggested skills" section in the document, naming which skills the next agent should call the Skill tool for.
+
+Do not duplicate content already captured in other artifacts (specs, plans, ADRs, issues, commits, diffs). Reference them by path or URL instead.
+
+Redact any sensitive information, such as API keys, passwords, or personally identifiable information.
+
+If the user passed arguments, treat them as a description of what the next session will focus on and tailor the doc accordingly.