blueprint-migration

# Blueprint Migration Expert skill for migrating blueprint structures between format versions. This skill is triggered by `/blueprint:upgrade` and handles version-specific migration logic. ## When to Use This Skill | Use this skill when... | Use blueprint-upgrade instead when... | |---|---| | You need version-specific migration logic (v3.0→v3.1, v3.2→v3.3, etc.) | You're invoking the user-facing upgrade workflow with prompts | | You need content hashing to detect manual modifications during migration | You want the high-level "upgrade my blueprint" entry point | | You're implementing a new migration step between format versions | Use blueprint-init instead when the project has no manifest yet | ## Core Expertise - Reading and parsing the blueprint manifest (`docs/blueprint/manifest.json` in v3.0+, or legacy `.claude/blueprints/.manifest.json` in v1.x/v2.x) for current version - Determining appropriate migration path based on version comparison - Executing versioned migration steps with user confirmation - Content hashing for detecting manual modifications - Safe file moves with rollback capability ## Canonical Manifest Filename - **v3.0+**: `docs/blueprint/manifest.json` (canonical, no dot prefix — produced by `/blueprint:init`). Some repos carry a legacy `docs/blueprint/.manifest.json` from earlier v3.0 migrations; upgrade tooling tolerates both via the `$MANIFEST` variable resolved in `/blueprint:upgrade` Step 2. - **v1.x/v2.x (historical)**: `.claude/blueprints/.man...