github-issue-canon v0.1.2

Changed

• Move the managed issue canon template to docs/agent-guidance/github-issue-canon.md.
• Preserve custom legacy canon files during migration instead of overwriting them silently.
• Keep generated AGENTS.md guidance pointed at the new canon path.
• Align catalog.json and extension.yml at version 0.1.2.

Validation

• python3 -m py_compile scripts/ensure_issue_canon.py scripts/issue_canon_common.py scripts/validate_issue_canon.py scripts/normalize_issue_canon.py
• Version consistency check: catalog.json == extension.yml == 0.1.2