Runs export: a truncated one counts the selection into X-Total-Count; the SDK and fluksio export warn how many runs were left out

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WgBfkm4rCmtd1T4vHWjEPx

docs/code/api.md

@@ -143,7 +143,9 @@ row's `created_at` as `before` for stable pagination.
 Exports also accept `ids` and `until`, with `format=csv` or `jsonl`.
 The metrics export is a long table; the runs export is one row per run.
 Use `params` and `metrics` to choose columns, including dotted paths into
-record outputs.
+record outputs. An export covers at most the newest 10 000 runs. When a
+selection matches more, the response carries `X-Truncated` with that cap and
+`X-Total-Count` with the number of runs the selection matched.
 
 Import takes `{"runs": [...]}`, records completed results without executing
 code, and deduplicates by `external_id`. See

docs/code/cli.md

@@ -297,6 +297,8 @@ select columns, including dotted paths such as `final_metrics.train_loss`.
 
 Both support `--flow`, repeated `--run ID`, `--group`, `--status`,
 `--since`, `--until` and `--local`. The run ID joins results to metrics.
+An export stops at the newest 10 000 runs, and when a selection matches more,
+the CLI and the Python client warn how many were left out.
 
 Output defaults to CSV on stdout. `-o FILE` writes a file; `--format jsonl`
 writes JSON Lines. Parquet requires `pip install 'fluksio[parquet]'` and