release(v4.8.3): bump framework and eight skills to 4.8.3 in lockstep; archive PR #46 reviews (two rounds)

Issue #42 stages 1-2: the SKILL.md code-block inventory as test data and
the removal of blocks the entry scripts already do. Merge-workspace review:
round 1 (@8d26106) claude agy grok PASS, codex NOT PASS (R1-R3); fixed in
17eba09 (docs, inventory data and the guard test only); round 2 4/4 PASS.
Full suite at 8d26106 1408 passed / 0 failed. Reports and the round-2
identity sidecars go to .agents/reports/<session>/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

.agents/skills/multi-agent-mux-create/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: multi-agent-mux-create
 description: "Create a new agent session (claude, antigravity/agy) in a dedicated herdr session for context-preserving long-running work. Always creates a herdr session — never backgrounds with nohup/disown. Writes the new session to .mam/agent-sessions.yaml. Use when you want to start a fresh agent (no prior UUID) for a new project workspace."
-version: 4.8.2
+version: 4.8.3
 author: godopu
 license: MIT
 platforms: [linux, macos]