chore: harden Gradle dependency reproducibility

feat: enable Gradle dependency locking for all configurations
feat: enforce strict lock-state usage in the build
feat: centralize repository declaration in settings.gradle
feat: enable strict Gradle dependency verification via gradle.properties
feat: add committed dependency lock state and verification metadata
fix: defer mockito agent resolution to test execution phase for locked builds
ci: validate reproducibility inputs before workflow builds
ci: include lock and verification inputs in workflow change detection
docs: establish explicit dependency update workflow for locks and verification metadata

.github/workflows/benchmarks.yml

@@ -11,6 +11,9 @@ on:
       - 'src/main/**'
       - 'src/jmh/**'
       - 'build.gradle'
+      - 'gradle.properties'
+      - 'gradle.lockfile'
+      - 'settings.gradle'
       - 'gradle/**'
       - 'gradlew'
       - 'gradlew.bat'
@@ -38,6 +41,14 @@ jobs:
       - name: Make Gradle executable
         run: chmod +x ./gradlew
 
+      - name: Verify reproducibility inputs
+        shell: bash
+        run: |
+          set -euo pipefail
+          test -f gradle.lockfile
+          test -f gradle.properties
+          test -f gradle/verification-metadata.xml
+
       - name: Run JMH benchmarks
         run: ./gradlew clean jmh --no-daemon