owner-build — Module stewardship on msdmd

owner-build is an application of msdmd. It records
who is responsible for a module in the same file as the implementation, so
agents do not invent authority or edit sensitive code without a review path.

Implementation status: this skill defines the OWNERS block and runner
contract. This repo does not currently ship an OWNERS runner script; consuming
repos should implement the contract below against their review policy.

Read msdmd/SKILL.md first if you have not. The block syntax, parser
contract, and visible gap rule are inherited.

The block

# === OWNERS ===
# id: chat_route_owner
#   owner: platform-runtime
#   steward: erin
#   review_required_for: auth, storage, user_data
#   escalation: platform-runtime
#   since: 2026-06-04
# === END OWNERS ===

Field schema

Required:

Field	Meaning
id	Stable ownership declaration id.
owner	Person, role, team, or hmmm if unresolved.

Optional:

Field	Meaning
steward	Person or role currently tending the module; use hmmm if unresolved.
review_required_for	Comma-separated change classes requiring review (auth, storage, network, user_data, admin, public_api, docs, etc.).
escalation	Person, role, team, channel, or hmmm for unresolved escalation.
backup_owner	Secondary owner or team.
requires	Comma-separated ids whose ownership affects this module.
since	Version or date the owner declaration was added.
deprecated	If present, marks ownership as scheduled for replacement.

Runner contract

An OWNERS runner MUST:

1. Parse every OWNERS block with the universal msdmd parser.
2. Report owner: hmmm, steward: hmmm, or escalation: hmmm as pending.
3. Report modules without OWNERS blocks as visible stewardship gaps.
4. Cross-check sensitive modules against review_required_for when
   BOUNDARIES metadata is available.
5. Exit non-zero for malformed required fields or missing owners in strict
   mode. Coverage gaps fail only in strict mode.

Agent behavior

When this skill is loaded before edits:

• Read OWNERS before making changes.
• If the intended edit touches a class named in review_required_for, call
  out the review requirement in the handoff or PR summary.
• Do not replace hmmm with a guessed person, role, or team.
• If ownership is absent, preserve the gap in output rather than pretending
  the committer or agent owns the file.

Reporting shape

• OWNED: owner is declared.
• PENDING: owner, steward, or escalation is hmmm.
• REVIEW_REQUIRED: edit class requires explicit review.
• GAP: module has no OWNERS block.

Anti-patterns

• Treating Git author, last committer, or PR opener as owner.
• Recording owner only in a central CODEOWNERS-like file while omitting the module-local declaration.
• Using ownership metadata to bypass review; it routes review, not permission.
• Guessing a team from a filename. Unknown is hmmm.

hmmm

• whether repo-level CODEOWNERS should generate suggested OWNERS blocks
• whether strict mode should require owners for all modules or only public/sensitive ones
• how to represent temporary stewardship during incidents