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>

agent/MEMORY.md

@@ -162,9 +162,9 @@ iteration would otherwise rediscover.
   effects carry a value, matchers take `match:` (§ windowrule migration).
 - grub `loadfont`s every `.pf2` in a theme dir — reuse a bundled DejaVu
   rather than shipping fonts (§ Distro branding).
-- `.claude/skills/*/SKILL.md` are **tracked thin shims** — the actual
-  instruction bodies live vendor-neutrally in `agent/` (VERIFICATION,
-  DELEGATION, THEME-DESIGN); edit those, not the shims. Still never
-  `git add -A` blindly: check `git status --short` for genuine strangers
-  first (`settings.local.json`, harness-dropped files) and commit with
-  explicit pathspecs (§ loop hygiene).
+- Agent instructions live vendor-neutrally in `agent/` (VERIFICATION,
+  DELEGATION, THEME-DESIGN; entry AGENTS.md) — `.claude/` is a thin
+  adapter (permissions + subagent defs only; skills were removed
+  2026-07-11). Never `git add -A` blindly: check `git status --short`
+  for genuine strangers first (`settings.local.json`, harness-dropped
+  files) and commit with explicit pathspecs (§ loop hygiene).