docs(ri-050): forge fail-closed docs + TASKS status catch-up (#1275)

- README + skills/mosaic-forge/SKILL.md: bare 'mosaic forge run/resume'
  now documents the typed FORGE_NO_EXECUTOR fail-closed behavior and
  --simulate for explicit typed simulation (fast-follow to RI-2-001).
- docs/release-integrity/TASKS.md: rows catch up to measured reality -
  CI green at pinned heads (#1276 2475, #1277 2476, #1278 2477, #1293
  2465, #1294 2466), review evidence recorded, RI-2-001 prior-red root
  cause corrected (CI-agent contention, superseding fleet-test theory).

Stacks on docs/ri-050-mission-bootstrap (#1276) - merge after #1278.

README.md

@@ -138,9 +138,9 @@ mosaic brain tasks
 mosaic brain conversations
 
 # Agent forge pipeline
-mosaic forge run
+mosaic forge run [--simulate]        # fails closed (FORGE_NO_EXECUTOR) with no executor wired; --simulate for typed simulated runs
 mosaic forge status
-mosaic forge resume
+mosaic forge resume [--simulate]     # same fail-closed rule as forge run
 mosaic forge personas
 
 # Structured logging