fix: retire legacy command shims from default surface

legacy-command-shims/commands/context-budget.md

@@ -0,0 +1,23 @@
+---
+description: Legacy slash-entry shim for the context-budget skill. Prefer the skill directly.
+---
+
+# Context Budget Optimizer (Legacy Shim)
+
+Use this only if you still invoke `/context-budget`. The maintained workflow lives in `skills/context-budget/SKILL.md`.
+
+## Canonical Surface
+
+- Prefer the `context-budget` skill directly.
+- Keep this file only as a compatibility entry point.
+
+## Arguments
+
+$ARGUMENTS
+
+## Delegation
+
+Apply the `context-budget` skill.
+- Pass through `--verbose` if the user supplied it.
+- Assume a 200K context window unless the user specified otherwise.
+- Return the skill's inventory, issue detection, and prioritized savings report without re-implementing the scan here.