fix: replace urllib with requests.Session in batch_validate.py

- Eliminates SSL latency by using `requests.Session` which reuses TCP
  connections and SSL handshake across all trace validation calls
- Removes manual `ssl`, `urllib.request`, `urllib.error` handling
- Also removes md file generation and summary functions — batch_validate
  now only validates traces and writes raw JSON output
- Add `logs/` to `.gitignore` to suppress runtime output folder

Author: Bharatram-altimate-ai

.gitignore

@@ -32,6 +32,7 @@ __pycache__/
 
 # Runtime logs
 *.log
+logs/
 
 # Large intermediate files at repo root (generated during benchmark runs)
 /queries.json