feat: add cloud session handoff skills

[k-ahlawat]

Summary

• add portable import-cloud-session and export-cloud-session skills for continuing coding work between local agents and CodeRabbit Cloud
• keep code transport in Git while the CodeRabbit CLI transfers encrypted SUMMARY.md and optional primary PLAN.md artifacts
• preserve clean-worktree, exact-commit, fast-forward-only, and explicit keep-local/keep-remote guardrails
• expose the skills through the repository's generic installer and existing Claude, Cursor, Gemini, and Antigravity packaging
• document both skills and align the plugin metadata with the upcoming 1.2.0 release

Dependency and rollout

Depends on coderabbitai/mono#24363 for the compatible CLI, API, Agent Platform, runtime, and task UI implementation.

Keep this PR in draft and do not publish the updated skills package before that implementation and CLI release are available. After rollout, coderabbitai/skills is the canonical source for these customer-facing skill bodies; coderabbitai/mono#24363 removes its development copies.

Verification

• both skill files match the previously exercised mono versions byte-for-byte
• quick_validate.py skills/import-cloud-session — passed
• quick_validate.py skills/export-cloud-session — passed
• all four plugin manifests parse as valid JSON
• gemini extensions validate . — passed
• git diff --check — passed

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Central YAML (base), Organization UI (inherited)

Review profile: CHILL

Plan: Enterprise

Run ID: 97de415e-9fab-403e-b489-7ecd5acd64eb

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

_{Comment @coderabbitai help to get the list of available commands.}