fix: retire legacy command shims from default surface

legacy-command-shims/commands/prompt-optimize.md

@@ -0,0 +1,23 @@
+---
+description: Legacy slash-entry shim for the prompt-optimizer skill. Prefer the skill directly.
+---
+
+# Prompt Optimize (Legacy Shim)
+
+Use this only if you still invoke `/prompt-optimize`. The maintained workflow lives in `skills/prompt-optimizer/SKILL.md`.
+
+## Canonical Surface
+
+- Prefer the `prompt-optimizer` skill directly.
+- Keep this file only as a compatibility entry point.
+
+## Arguments
+
+`$ARGUMENTS`
+
+## Delegation
+
+Apply the `prompt-optimizer` skill.
+- Keep it advisory-only: optimize the prompt, do not execute the task.
+- Return the recommended ECC components plus a ready-to-run prompt.
+- If the user actually wants direct execution, say so and tell them to make a normal task request instead of staying inside the shim.