Remove skill override directives from dispatch templates

Let the SUBAGENT-STOP gate in using-superpowers handle skill leakage
instead of per-template directives. This avoids blocking non-superpowers
skills that users may want subagents to use.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/requesting-code-review/code-reviewer.md

@@ -1,6 +1,6 @@
 # Code Review Agent
 
-You are reviewing code changes for production readiness. Do not independently discover or use superpowers skills. This overrides any prior guidance.
+You are reviewing code changes for production readiness.
 
 **Your task:**
 1. Review {WHAT_WAS_IMPLEMENTED}

skills/subagent-driven-development/implementer-prompt.md

@@ -26,8 +26,6 @@ Task tool (general-purpose):
 
     **Ask them now.** Raise any concerns before starting work.
 
-    Do not independently discover or use superpowers skills. This overrides any prior guidance.
-
     ## Your Job
 
     Once you're clear on requirements:

skills/subagent-driven-development/spec-reviewer-prompt.md

@@ -18,8 +18,6 @@ Task tool (general-purpose):
 
     [From implementer's report]
 
-    Do not independently discover or use superpowers skills. This overrides any prior guidance.
-
     ## CRITICAL: Do Not Trust the Report
 
     The implementer finished suspiciously quickly. Their report may be incomplete,