This commit introduces two key performance and safety improvements to the repository's maintenance scripts:
1. **Optimize `scripts/test_automation.py`**:
- Replaced `concurrent.futures.ProcessPoolExecutor` with sequential execution for the integration test suite.
- For short-lived subprocess calls, the overhead of starting multiple Python processes for isolation was significantly higher than the execution time of the tests themselves.
- **Impact**: Reduced total execution time by ~26% (from 4.0s to 2.9s) and ensured deterministic, ordered output.
2. **Optimize `scripts/ci_validate_repo.py`**:
- Consolidated two separate file iteration loops into a single `validate_files` pass.
- Implemented a "size-before-read" check using `path.stat().st_size` before calling `path.read_bytes()`.
- **Impact**: Improved memory efficiency and prevented potential Out-Of-Memory (OOM) errors by ensuring large files are rejected before being read into memory. Consolidating the loop also reduces redundant file system operations.
Verified both changes by running the integration tests and the validator manually.
