Add outbound CloudEvents emitter

[JE-Chen]

Devex batch (from multi-agent web research; verified absent — repo received webhooks but couldn't emit). Full layers + tests + EN/Zh v49 docs + README.

Feature (utils/events, pure-stdlib)

• to_cloudevent wraps data in a CloudEvents 1.0 (CNCF) envelope (auto specversion/id/time); EventEmitter binds a source and dispatches to an injectable sink; post_cloudevent POSTs over the egress-guarded HTTP client (interop: Knative, Azure Event Grid, iPaaS, generic webhooks).
• Transport injectable (sink/poster) → unit-tested with no network.
• Executor AC_emit_event; MCP ac_emit_event; Builder under Tools.

Verification

• 9 tests pass (envelope fields, unique ids, explicit id/time, default+injected sink, injected poster, executor round-trip, wiring, facade); ruff clean; radon no CC≥C; bandit clean; PySide6-free.
• Rebased onto dev after the asset store (Add environment-scoped typed asset store #256) merge.

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

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🟢 Metrics 28 complexity · 0 duplication

Metric	Results
Complexity	28
Duplication	0

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud