ci: skip e2e for tools-only and docs-only PRs

Path filter excludes tools/**, FitnessEvaluator*, docs/**, *.md.
Branch protection now requires ci/woodpecker/pr/ci (always runs)
instead of e2e (which may be skipped).

.woodpecker/e2e.yml

@@ -7,6 +7,12 @@ name: e2e
 
 when:
   event: pull_request
+  path:
+    exclude:
+      - "tools/**"
+      - "onchain/test/FitnessEvaluator*"
+      - "docs/**"
+      - "*.md"
 
 clone:
   git: