fission-ai__openspec/openspec/changes/add-antigravity-support/tasks.md

1. CLI init support

• 1.1 Surface Antigravity in the native-tool picker (interactive + --tools) so it toggles alongside other IDEs.
• 1.2 Generate .agent/workflows/openspec-proposal.md, openspec-apply.md, and openspec-archive.md with YAML frontmatter restricted to a single description field for each stage and wrap the body in OpenSpec markers.
• 1.3 Confirm workspace scaffolding covers missing directory creation and re-run scenarios so repeated init refreshes the managed block.

2. CLI update support

• 2.1 Detect existing Antigravity workflow files during openspec update and refresh only the managed body, skipping creation when files are missing.
• 2.2 Ensure update logic preserves the description frontmatter block exactly as written by init, including case and spacing, and refreshes body templates alongside other tools.

3. Templates and tests

• 3.1 Add shared template entries for Antigravity that reuse the Windsurf copy but target .agent/workflows plus the description-only frontmatter requirement.
• 3.2 Expand automated coverage (unit or integration) verifying init and update produce the expected file paths and frontmatter + body markers for Antigravity.