fix(ci): skip gate-passed check for bot PRs

Dependabot PRs cannot run kanon gate locally, so the Gate-Passed
trailer check fails unconditionally. Skip the verification step
when the PR author is a bot.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Gate-Passed: kanon v0.1.0 (menos, 2026-03-26T19:00:56-05:00)
Gate-Checks:

Author: Cody Kickertz

.github/workflows/gate-verify.yml

@@ -15,7 +15,19 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Check for bot PR
+        id: bot-check
+        run: |
+          author="${{ github.event.pull_request.user.login }}"
+          if [[ "$author" == *"[bot]" || "$author" == "dependabot"* ]]; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            echo "Skipping gate check for bot author: $author"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
+
       - name: Verify Gate-Passed trailer
+        if: steps.bot-check.outputs.skip != 'true'
         run: |
           commits=$(git log --format="%H" origin/main..HEAD)
           if [ -z "$commits" ]; then