[EXPERIMENTAL] feat: stream live apply logs to audit API

[brandonmontijo]

Summary

• Buffers apply stdout line-by-line and flushes to POST /log_chunk every 10 lines or 5s
• No-op when audit_api_url is not set — existing behavior unchanged
• Version bump to 0.10.26

Test plan

• Point audit_api_url at devops-testing, run tf apply, confirm chunks POST successfully
• Confirm apply still succeeds if chunk POST fails (errors logged, not raised)
• Unit tests added for _post_log_chunk and the on_chunk buffering/failure-handling in execute_command

Testing before merge

This feature spans 3 repos — terraform-audit-api#193 and launchpad#130 — and can't be verified in isolation:

1. Deploy terraform-audit-api#193 to devops-testing (creates the log_chunks table + new endpoints).
2. Install this branch locally and run a real tf apply/destroy against a devops-testing directory with audit_api_url pointed at that deploy. Confirm POST /log_chunk succeeds and local console output isn't stalling.
3. Run launchpad#130 locally against the devops-testing API, trigger the same apply from the tfaudit UI, confirm the Output page streams live and swaps to the full output on completion.
4. Repeat step 3 for a failing apply and for two concurrent applies in different directories.