feat: enforce contribution intake policy

[wibus-wee]

Related issue

#92

Problem / pressure

External contributions need durable intake rules: maintainers must see why a change exists, what risks deserve review, whether prior design discussion is substantive, and whether a large diff arrived without coordination. An Agent must not create an Issue and immediately treat it as approval, malformed Issues need actionable warnings, and invalid PR bodies need a fair but finite correction window.

Summary

• Remove Author type and Sharing consent from the PR template; require a complete public Context handoff for every external PR and reject N/A/redacted context.
• Require a full Lody Issue URL in every external PR body, while stating that a URL is only a mechanical gate and not proof of approval.
• Require Issue Forms and the PR Template to tell authoring Agents that a self-created Issue is not approval, explain the policy to the author-side user, and wait for explicit maintainer agreement before implementation or a PR.
• Add required Bug and Feature confirmations that contributors will wait for maintainer agreement.
• Warn non-owner, non-bot Issue authors when titles, required sections, or confirmations do not match the Issue Forms; clear the warning after a valid edit.
• Mark invalid PR bodies, preserve their original invalid timestamp, clear the state when fixed, and close unresolved PRs after seven days.
• Mark external PRs over 200 changed lines without an Issue URL as status:pr-too-large, but give them the same seven-day body correction window instead of closing immediately.
• Re-close body-expired PRs when reopened without deleting contributor branches.
• Keep forms/templates, pure checkers, GitHub state policies, path labels, and event orchestration in separate maintainable files.

Before / after

Before	After
An Agent could create an empty Issue and immediately claim it as permission for a large PR.	Issue creation is explicitly not approval; maintainers must agree first, malformed Issues are warned, and invalid or oversized-unreferenced PRs get one seven-day correction window.

Test plan

• Deterministic complete Bug and Feature samples plus rejected title, empty-answer, unchecked-confirmation, and missing-agreement cases.
• Issue policy simulations: MEMBER enforcement, OWNER/bot exemption, first warning, and valid cleanup.
• Deterministic PR-body samples: complete body, missing Issue, old handoff heading, and N/A/redacted prefixes.
• Deterministic size-policy simulations: 200/201-line boundary, Issue bypass, owner/member exemption, first warning, valid cleanup, and assertion that no PR close API is available or called.
• Node syntax checks for all policy modules.
• Actionlint v1.7.7 for all affected workflows.
• Oxlint 1.61.0 with zero warnings or errors.
• Prettier 3.8.2 and git diff --check.
• pnpm check:public-boundary.
• Read-only dry-run against all current open external PRs.

Context handoff

Instructions for reviewing agents

• Review focus: Trace trusted-checkout boundaries, Issue/size warning cleanup, the single body-expiry timer, and the final latest-body guard before closure.
• Decisions to challenge: Challenge the OWNER-only Issue exemption, mirrored Issue Form fields, mandatory prior maintainer agreement, 200-line threshold, full Issue URL requirement, and retroactive PR-body audit.
• Plausible failures / evidence gaps: Form edits could drift from the checker, API failures could leave partial feedback, URL syntax cannot prove approval, and live event/schedule behavior remains post-merge evidence.

Authoring context

• User goal / directives: Make Agents wait for explicit maintainer agreement instead of self-opening an Issue and immediately submitting a PR; require useful public context and give oversized PRs seven days rather than closing them immediately.
• Constraints / non-goals: Do not classify PR author type, do not offer a context-sharing opt-out, never invent notice or approval, exempt only owners from Issue format, separate policies by responsibility, and do not machine-judge maintainer agreement.
• Risk-bearing decisions: Put the wait-for-approval rule in Issue Forms, PR Template, and contributor guidance; mirror required Issue confirmations in a checker; apply the PR schema to all open external PRs; and make size warnings share the body timer rather than own closure state.
• Destructive or irreversible behavior: Issue and size enforcement only label/comment; an invalid external PR closes after the shared seven-day deadline and cannot reopen, but contributor branches and commits are preserved.
• Deliberately not done or tested: Repository rulesets were not changed, existing Issues are not batch-backfilled, approval and Agent-to-user notice are not machine-judged, and live event/scheduled behavior cannot execute before merge.
• Unknowns / confidence: Schema, boundary, lint, formatting, workflow, and state simulations pass; first live label/comment reconciliation remains the main operational unknown.