fix(llm): retry rate-limited (429) batches instead of dropping them

[keshprad]

Summary

• retry provider rate-limit failures in both synchronous and asynchronous LLM batch loops with a bounded 5s/15s/30s/60s/60s schedule
• honor numeric Retry-After values up to 120 seconds, including for models with native provider retries
• record exhausted rate-limit retries as llm_rate_limit_retries_exhausted in the inspection ledger

Validation

• make lint — passed
• make format-check — passed
• pytest -q tests/nodes/test_llm_analyzer_base.py tests/test_inspection_ledger.py — 171 passed
• unit suite — 2213 passed, 13 skipped, 4 xfailed; seven SSRF hostname tests fail because GitHub/GitLab resolve to private/internal addresses in this environment. The exact same seven tests fail on the untouched 29b0dc8 base.

Attribution

Applied from the attached signed-off patch while preserving Devin AI as the commit author and the original Signed-off-by/Co-Authored-By trailers.