release: v0.22.4 portable Zoo Code integration

[tbitcs]

Summary

Implements and closes #307 by making Specsmith the canonical distribution point for reusable Zoo Code integration assets.

Added

• specsmith zoo-code setup --project-dir .
• specsmith zoo-code doctor --project-dir .
• specsmith zoo-code uninstall --project-dir .
• reusable global Specsmith rules, slash commands, and skills under ~/.roo
• safe backup/adoption of reserved global paths
• managed manifests and stale-asset cleanup
• project MCP merge that preserves unrelated servers
• migration of recognized generic Specsmith workspace duplicates
• focused lifecycle and CLI registration tests
• portable integration and operator documentation

Safety

• customized workspace files are preserved
• --preserve-existing refuses adoption of unmanaged global files
• uninstall removes only marker-owned assets
• the MCP entry is removed only when it still matches the managed value
• --dry-run, --scope, --global-roo, and ROO_GLOBAL_DIR are supported

Release

• bumps the package revision from 0.22.3 to 0.22.4
• updates the source fallback version
• updates Zoo Code documentation and package metadata

Validation

Focused lifecycle tests cover setup, doctor, idempotence, backup/adoption, preserve-existing conflicts, MCP merge, duplicate cleanup, stale cleanup, safe uninstall, and CLI registration.

Closes #307