fix: clean node_modules before npm ci to avoid ENOTEMPTY error

CI was failing because npm ci couldn't remove stale node_modules
directory. Explicitly removing it first ensures a clean install.

.woodpecker.yml

@@ -19,6 +19,7 @@ steps:
       - apk add --no-cache curl
       - npm --version | cat
       - node --version | cat
+      - rm -rf node_modules
       - npm ci
       - npm test
     when:
@@ -32,6 +33,7 @@ steps:
     commands:
       - echo "nameserver 1.1.1.1" > /etc/resolv.conf
       - echo "nameserver 1.0.0.1" >> /etc/resolv.conf
+      - rm -rf node_modules
       - npm ci
       - echo "=== Scanning for unused files/exports/dependencies (knip) ==="
       - npx --yes knip || echo "knip found issues (non-blocking)"