feat(odin): Add support for streaming log files to CDF Files

[vikramlc-cognite]

Summary

Completes the fetch_logs action by wiring the upload loop: candidate log files are streamed to CDF Files via upload_bytes, with per-file result tracking and structured success metadata reported back to Odin.

Type of change

• New feature (non-breaking change that adds functionality)

What changed

• _log_upload_action.py: Added _FileUploadResult dataclass, _file_external_id(), and _upload_candidate(). The fetch_logs_action now snapshots the current-day file size before spawning uploads, submits candidates to a ThreadPoolExecutor, and calls ctx.set_result() with aggregated counts and a per-file JSON array in result_metadata.
• actions.py: Added ActionContext.set_result(message, *, metadata) so actions can declare structured success data without changing the ActionTarget signature.
• base.py: _handle_custom_action success path now forwards ctx._result_message and ctx._result_metadata into the ActionUpdate(succeeded) call.
• test_log_upload_action.py: 9 new tests covering _file_external_id naming, _upload_candidate for rotated files, BoundedReader usage for current-day files, oversized file skipping, CDF upload errors, and end-to-end fetch_logs_action result metadata (partial failures, all-missing, upload failures still report succeeded).
• test_action_dispatch.py: 1 new test verifying set_result values propagate into the succeeded ActionUpdate.

Why it changed

• Implements upload execution and result reporting for the fetch_logs action (EDG-371). Prior commits established parameter validation, candidate file enumeration, and BoundedReader; this commit closes the loop end-to-end.

What to focus on during review

• Snapshot-before-threads ordering: snapshot_size is captured via stat() before the ThreadPoolExecutor is created. This is load-bearing - if the snapshot happened inside the thread, it would race with the logger appending to the file, making BoundedReader's ceiling unreliable.
• Partial failure semantics: A file that fails to upload results in status="failed" in result_metadata["files"], but the action still reports ActionStatus.succeeded with failed_files > 0. The caller (Odin operator) sees the breakdown and decides whether to re-trigger.
• ctx._extractor access: fetch_logs_action reads ctx._extractor.cognite_client and ctx._extractor.connection_config.integration.external_id. This is internal framework access - _log_upload_action.py is _-prefixed and co-located in the same package. Exposing these on the public ActionContext API would unnecessarily widen the surface for user-authored actions.

Test evidence

tests/test_unstable/test_log_upload_action.py 40 passed
tests/test_unstable/test_action_dispatch.py passed
ruff: clean, mypy: clean

Risks and unknowns

• DEFAULT_CONCURRENT_UPLOADS = 1 keeps uploads sequential. Safe on constrained networks; parallelism is a one-line change when needed.
• MAX_FILE_SIZE_BYTES = 4 GiB - should be validated against the SDK's actual per-request upload limit.

Rollout and rollback

N/A - triggered only on explicit Odin dispatch. No config changes or migrations.

Checklist

• Self-reviewed the diff
• Tests added or updated
• Docs updated (N/A - internal framework)
• No secrets, credentials, or PII committed
• Breaking changes called out above and communicated to affected teams

[gemini-code-assist]

Code Review

This pull request introduces a BoundedReader to cap log file uploads to a point-in-time snapshot size, preventing Content-Length mismatches on active logs. It also updates the log upload action to support concurrent uploads and report structured results. The review feedback suggests implementing a seek method in BoundedReader to support HTTP client retries, capping the snapshot size at file-open time to avoid truncation race conditions, and adding corresponding unit tests for the new seek behavior.

[vikramlc-cognite]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces concurrent log file uploads to CDF Files in the fetch_logs action, including size snapshotting for the current-day log file to prevent content-length mismatches. It also adds support for reporting action execution results and metadata back to the dispatcher. The review feedback highlights a potential resource leak in _upload_candidate where a file is opened outside of a with statement, and suggests refactoring it to use a standard with open(...) as f: block.

[vikramlc-cognite]

/gemini review

[gemini-code-assist]

Code Review

This pull request enhances the log upload action by introducing structured upload results, file size snapshotting for active log files using a BoundedReader, and the ability to propagate successful action results and metadata to CDF. The review feedback correctly identifies a critical issue where BoundedReader lacks a seek method, which can break HTTP retries during file uploads and lead to failures or corrupted uploads.

[Yaseen-A-Khan]

I have a few nits and comments, please review them