feat(ci): add PR pipeline and system-test workflows

New workflows:
- pr-build.yml: multi-OS build matrix (macOS, Ubuntu, RockyLinux, Debian11)
  and changed-line/overall coverage gate
- pr-check.yml: PR title/body lint + Checkstyle
- pr-reviewer.yml: scope-based reviewer auto-assignment
- pr-cancel.yml: cancel in-progress runs when PR is closed unmerged
- system-test.yml: spin up FullNode and run the system-test suite

Existing workflows:
- codeql.yml: bump to v4/v5 actions, switch to manual build-mode with
  JDK 8, add paths-ignore for docs-only changes
- math-check.yml: bump checkout/upload-artifact/github-script versions

Author: halibobo1205

.github/workflows/codeql.yml

@@ -6,6 +6,9 @@ on:
   pull_request:
     # The branches below must be a subset of the branches above
     branches: [ 'develop' ]
+    paths-ignore: [ '**/*.md', '.gitignore', '**/.gitignore', '.editorconfig',
+                    '.gitattributes', 'docs/**', 'CHANGELOG', '.github/ISSUE_TEMPLATE/**',
+                    '.github/PULL_REQUEST_TEMPLATE/**', '.github/CODEOWNERS' ]
   schedule:
     - cron: '6 10 * * 0'
 
@@ -29,36 +32,25 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v5
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v3
+      uses: github/codeql-action/init@v4
       with:
         languages: ${{ matrix.language }}
-        # If you wish to specify custom queries, you can do so here or in a config file.
-        # By default, queries listed here will override any specified in a config file.
-        # Prefix the list here with "+" to use these queries and those in the config file.
+        build-mode: manual
 
-        # For more details on CodeQL's query packs, refer to: https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#using-queries-in-ql-packs
-        # queries: security-extended,security-and-quality
-
-    # Autobuild attempts to build any compiled languages (C/C++, C#, Go, Java, or Swift).
-    # If this step fails, then you should remove it and run the build manually (see below)
-    - name: Autobuild
-      uses: github/codeql-action/autobuild@v3
-
-    # ℹ️ Command-line programs to run using the OS shell.
-    # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
-
-    #   If the Autobuild fails above, remove it and uncomment the following three lines.
-    #   modify them (or add more) to build your code if your project, please refer to the EXAMPLE below for guidance.
+    - name: Set up JDK 8
+      uses: actions/setup-java@v5
+      with:
+        java-version: '8'
+        distribution: 'temurin'
 
-    # - run: |
-    #     echo "Run, Build Application using script"
-    #     ./location_of_script_within_repo/buildscript.sh
+    - name: Build
+      run: ./gradlew build -x test --no-daemon
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v3
+      uses: github/codeql-action/analyze@v4
       with:
         category: "/language:${{matrix.language}}"

.github/workflows/math-check.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Check for java.lang.Math usage
         id: check-math
@@ -55,14 +55,14 @@ jobs:
 
       - name: Upload findings
         if: steps.check-math.outputs.math_found == 'true'
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: math-usage-report
           path: math_usage.txt
 
       - name: Create comment
         if: github.event_name == 'pull_request' && steps.check-math.outputs.math_found == 'true'
-        uses: actions/github-script@v6
+        uses: actions/github-script@v8
         with:
           script: |
             const fs = require('fs');