release(v4.7.4): bump framework and eight skills to 4.7.4 in lockstep; archive PR #38 merge-side reviews

Issue #34: the loop waits for the creator job's sub-jobs, reviewers get
the sub-job table as evidence, a run with sub-jobs voids a round whose
source changed during review, and a pane caller reaches an agent of
another workspace on its own server. VERSIONS.md carries the entry; the
merge-side reports (round 1 @ed293dc and round 2 @e80186f with identity
sidecars, base ed293dc -> head e80186f, evidence review-tree) are archived
under .agents/reports/<session>/.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

.agents/skills/lib.sh

@@ -29,7 +29,7 @@ export WORKSPACE_ROOT
 # Framework semantic version. Single runtime source of truth; kept in lockstep
 # with VERSIONS.md and the 8 SKILL.md frontmatters by tests/test_version_consistency.py.
 # NOTE: unlike other MAM_* variables this one is intentionally NOT env-overridable.
-MAM_VERSION="4.7.3"
+MAM_VERSION="4.7.4"
 export MAM_VERSION
 AGENT_SESSIONS_YAML="${AGENT_SESSIONS_YAML:-$WORKSPACE_ROOT/.mam/agent-sessions.yaml}"