release(v4.4.3): bump framework and eight skills to 4.4.3 in lockstep

PATCH release for the fix/issue-10-11-13-15 branch (Issue #10 agy purge
sidecars, #11 orc_onboard message, #13 orchestrator conversation purge,
#15 workspace-anchored job registry). No code logic changes.

- lib.sh MAM_VERSION, lib_py/loop/eager.py FRAMEWORK_VERSION and the eight
  SKILL.md frontmatters (create, stop, resume, status, monitor, delegate-job,
  loop, orc-onboard) move from 4.4.2 to 4.4.3
- VERSIONS.md: current release v4.4.3 (2026-09-13 KST), the eight-row skill
  matrix, and a v4.4.3 changelog section in the v4.4.2 format covering the
  agy purge sidecars/annotation/presence lock and residual_artifacts,
  `lib_py.agents purge` and `orc_onboard.sh --remove --purge-conversation`
  with their exit codes, the past-tense message, the MAM_JOBS_DIR ->
  WORKSPACE_ROOT -> cwd registry/log resolution and the 20 new tests
- README, README.ko, BOOTSTRAP and BOOTSTRAP.ko badges and the MESSAGING.md
  "Applies to" header follow the current version; historical 4.4.2 mentions
  (v4.4.2 changelog, reviewer reports) stay as history

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HCGpJXhSZasJLU38ksDghe

.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="4.4.2"
+MAM_VERSION="4.4.3"
 export MAM_VERSION
 AGENT_SESSIONS_YAML="${AGENT_SESSIONS_YAML:-$WORKSPACE_ROOT/.mam/agent-sessions.yaml}"