feat(history-rewrite): Enhance history rewrite process with detailed backup and validation steps

- Added a comprehensive plan for history rewrites in `docs/plans/history_rewrite.md`, including backup requirements and a checklist for destructive operations.
- Created a QA report for history-rewrite scripts in `docs/reports/qa_report.md`, summarizing tests, findings, and recommendations.
- Introduced `check_refs.sh` script to list branches and tags, saving a tarball of tag references.
- Updated `clean_history.sh` to include non-interactive mode and improved error handling for backup branch pushes.
- Enhanced `preview_removals.sh` to support JSON output format and added shallow clone detection.
- Added Bats tests for `clean_history.sh` and `validate_after_rewrite.sh` to ensure functionality and error handling.
- Implemented pre-commit hook to block commits to `data/backups/` directory.
- Improved validation script to check for backup branch existence and run pre-commit checks.
- Created temporary test scripts for validating `clean_history.sh` and `validate_after_rewrite.sh` functionality.

.github/workflows/history-rewrite-tests.yml

@@ -0,0 +1,32 @@
+name: History Rewrite Tests
+
+on:
+  push:
+    paths:
+      - 'scripts/history-rewrite/**'
+      - '.github/workflows/history-rewrite-tests.yml'
+  pull_request:
+    paths:
+      - 'scripts/history-rewrite/**'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout with full history
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y bats shellcheck
+
+      - name: Run Bats tests
+        run: |
+          bats ./scripts/history-rewrite/tests || exit 1
+
+      - name: ShellCheck scripts
+        run: |
+          shellcheck scripts/history-rewrite/*.sh || true