fix(build): ignore node_modules and package-lock.json to prevent :dirty version

The npmInstall task (dependency of bundleScanner → processResources) writes
node_modules/ and package-lock.json into methodatlas-discovery-typescript/.
Because these paths were absent from .gitignore the Palantir git-version
plugin detected them as untracked files via git status --porcelain and
appended :dirty to the version — making every task after the first
./gradlew test appear to run on a dirty tree.

To opt into fully reproducible builds (npm ci instead of npm install),
remove the package-lock.json line, run npmInstall once, and commit the
generated lock file.

Author: leogalambos

.gitignore

@@ -90,6 +90,17 @@ local.properties
 # PMD plugin conf
 .pmd
 
+##---------------------------------------------------------------------------------------- Node.js
+
+# npm dependency tree — never commit; regenerated by npmInstall on every clean checkout.
+node_modules/
+
+# Lock file — ignored here so a fresh checkout uses 'npm install' instead of 'npm ci'.
+# To switch to fully reproducible builds, remove this line, run
+# ./gradlew :methodatlas-discovery-typescript:npmInstall once, and commit the generated
+# methodatlas-discovery-typescript/package-lock.json.
+package-lock.json
+
 ##---------------------------------------------------------------------------------------- Gradle
 .gradle
 **/build/