chore(agent): drop .claude/skills — AGENTS.md carries the routing

The skill shims became redundant once the auto-loaded entry point
(CLAUDE.md → AGENTS.md) explicitly instructs reading VERIFICATION.md /
THEME-DESIGN.md; their only remaining value was explicit /nomarchy and
/theme invocation. The adapter is now permissions + subagent defs only.
References updated (AGENTS.md, agent/README.md, docs/README.md, README
tree, MEMORY.md hygiene note).

Verification: V0 (docs/meta only).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

README.md

@@ -86,7 +86,7 @@ Flat on purpose. Two module trees, one options file each, no hidden layers.
 ├── agent/                         # agent instructions + loop state — map: agent/README.md
 │                                  #   BACKLOG (executable queue), LOOP, VERIFICATION, …
 ├── AGENTS.md                      # agent entry, any vendor (CLAUDE.md symlinks here)
-├── .claude/                       # Claude Code adapter: permissions + subagent/skill shims
+├── .claude/                       # Claude Code adapter: permissions + subagent defs
 └── tools/                         # maintainer-only
     ├── import-palettes.py         #   converts old-distro themes → JSON + assets
     ├── test-live-iso.sh           #   build the ISO + boot it in QEMU