release: v5.0.0 — conservative subagent support (parent seed + child recovery)

- Add workspace resolution helpers (isSubagentSession, parseParentAgentId, resolveAgentWorkspace)
- Parent→Child seeding: inject parent CURRENT_STATE.md into subagent context at startup
- Child→Parent recovery: new subagent_ended hook reads child unsurfaced results, merges into parent
- Add subagentSeed and subagentRecovery config keys (both default: true)
- Add /mc subagents command for cross-workspace state overview
- Bump lifecycle plugin to v5.0.0, mc-plugin to v2.1.0

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

mc-plugin/openclaw.plugin.json

@@ -2,7 +2,7 @@
   "id": "mc",
   "name": "Memory Continuity Commands",
   "description": "Slash commands for Memory Continuity — /mc state, /mc history, /mc search, /mc settings, etc.",
-  "version": "2.0.0",
+  "version": "2.1.0",
   "author": { "name": "dtzp555-max", "url": "https://github.com/dtzp555-max" },
   "license": "MIT",
   "category": "commands",