feat(release): self-determination - ensure at launch, drift warnings, M20 packages/* decision (#38)

- release.sh ensure: aligned no-op; drift -> package-if-needed + health-gated
  activate (M3 gate-then-flip, automated)
- ensure_release_aligned in common.sh: invoked by hello/verify/agent;
  MOSAIC_ENSURE_SKIP guards recursion; run-task warns on drift without
  auto-aligning (workers/suites never trigger builds or model gates)
- ROADMAP: M20 decision recorded - v2 adopts packages/* monorepo at usurpation
- BUILD-LOG Phase 20 + tool-race process note

Live-verified: post-reset pointer loss auto-restored via health-gated
ensure; drift warning fires on desired-version bump; idempotent no-op on
aligned state.

Closes #38

scripts/agent.sh

@@ -40,6 +40,7 @@ case "$NAME" in *[!A-Za-z0-9._-]*|'') echo "agent: invalid agent name" >&2; exit
 load_config
 load_release
 bootstrap_runtime_dir
+ensure_release_aligned
 
 # Onboarding gate (M16): a TUI agent cannot launch without a user profile.
 # The onboarding wizard runs automatically here - the TTY is already yours.