feat(mcpl): render manifest freshness in admin listing

[Meganeuridae]

Summary

• render Agent Framework manifest freshness in mcpl_list: validated revision, fetch time, and grant-negotiation time
• distinguish older Framework versions as manifest=unknown for rolling upgrades
• quote and bound the server-authored revision before placing it on a model-facing text surface
• add an Unreleased changelog entry

Depends on anima-research/agent-framework#87. This remains a narrow listing-only follow-up: it adds no retained state and reads only the fetched-and-acted-on transport facts introduced by Agent Framework #84.

Testing

• bun test test/mcpl-admin-module.test.ts (11/11 pass)
• bun test (604/604 pass)
• git diff --check
• tsc --noEmit is currently red on an untouched detached origin/main checkout too because the registry Agent Framework lacks the already-merged nudgeAgent and McplServerConfig.accessProvider declarations; this patch does not introduce either mismatch.