fix(hooks): silence stderr in fail-open dispatch path

Claude Code surfaces stderr as "hook error" even with exit 0. Remove
the stderr message when binary is not found to eliminate the error
display while still failing open with {"decision":"approve"}.

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

Author: rand

scripts/hook-dispatch.sh

@@ -96,7 +96,6 @@ if [ -f "$LEGACY_SCRIPT" ]; then
     exec python3 "$LEGACY_SCRIPT"
 fi
 
-# Nothing found - fail open to avoid blocking
-echo "Hook not found: $HOOK_NAME" >&2
+# Nothing found - fail open silently to avoid hook error display
 echo '{"decision":"approve"}'
 exit 0