fix: harden mission control start/play status flows

[hopeatina]

Summary

• fix entity action status mapping so workstream start/resume/pause/complete map to canonical statuses (active, paused, completed) and stop 500s on /orgx/api/entities/.../start
• add regression coverage for dynamic entity action routes, including pause/resume and unknown-action rejection
• improve mission control initiative rows with explicit inline explanations when Start is disabled (active, degraded sync, blocked/completed states)
• add user-visible success/error feedback for workstream Start/Resume/Pause/Block/Complete actions in detail modal
• correct activity status classification so completed delegation/run events are not mislabeled as Issue due to stale session blockers
• update fallback initiative description generation/merge behavior to avoid contradictory copy like active with zero active workstreams

Test plan

• npm run typecheck
• npm run build:core
• npm run build:dashboard
• npm run test:hooks
• node --test tests/http/entity-actions-route.test.mjs
• curl -X POST http://127.0.0.1:18789/orgx/api/entities/workstream/e8869f78-1aea-4614-b105-37fc80727e19/start (returns 200 + active)
• Playwright verification screenshots:
  • qa-artifacts/2026-03-04-fix-verification/01-activity-completed-filter-no-issue-badges.png
  • qa-artifacts/2026-03-04-fix-verification/02-mission-control-start-disabled-inline-reason.png

Notes

• excluded from commit: local QA artifact directories and local report/script scratch files