Fix: Resolve CSV output generation failure in benchmarks (#435)

## Summary

This PR fixes two critical bugs that cause the `guidellm benchmark`
command to crash when using the `--output-formats csv` option. These
changes ensure that CSV reports are generated reliably and correctly.

## Details

1.  Fix `AttributeError`**:
In `src/guidellm/benchmark/output.py`, a `hasattr` check has been added
to the `_get_benchmark_status_metrics_stats` function.
This check ensures that the code only attempts to access status
attributes (e.g., `successful`) on metric objects that actually possess
them (like `StatusDistributionSummary`). It safely skips composite
metrics such as `GenerativeTextMetricsSummary`, thus preventing the
`AttributeError`.

 2.  Fix `KeyError`**:
The data flow for benchmark compilation has been refactored to ensure
the original data configuration (`args.data`) is correctly propagated.
The method signatures for `Benchmarker.run` (in `benchmarker.py`) and
`GenerativeBenchmark.compile` (in `schemas.py`) were updated to accept a
`data` parameter.
`args.data` is now passed in during the `benchmarker.run` call within
`benchmark_generative_text` (in `entrypoints.py`).
As a result, the `benchmark.benchmarker.requests` field in the final
`GenerativeBenchmark` object now directly stores the raw data
configuration, which resolves the `KeyError` in `output.py`.

## Test Plan

guidellm benchmark
--target "http://x.x.x.x:x/"
--processor "Qwen/Qwen3-8B-FP8"
--rate-type "concurrent"
--rate 1
--max-requests 10
--data "prompt_tokens=32,output_tokens=32,samples=1"
--output-formats csv

## Related Issues

#434

- Resolves #

---

- [x] "I certify that all code in this PR is my own, except as noted
below."

## Use of AI

- [ ] Includes AI-assisted code completion
- [ ] Includes code generated by an AI application
- [ ] Includes AI-generated tests (NOTE: AI written tests should have a
docstring that includes `## WRITTEN BY AI ##`)

Author: markurtz

src/guidellm/benchmark/benchmarker.py

@@ -57,6 +57,7 @@ async def run(
         backend: BackendInterface[RequestT, ResponseT],
         profile: Profile,
         environment: Environment,
+        data: list[Any],
         progress: BenchmarkerProgress[BenchmarkT] | None = None,
         sample_requests: int | None = 20,
         warmup: float | None = None,
@@ -149,6 +150,7 @@ async def run(
                     environment=environment,
                     strategy=strategy,
                     constraints=constraints,
+                    data=data,
                 )
                 if progress:
                     await progress.on_benchmark_complete(benchmark)

src/guidellm/benchmark/entrypoints.py

@@ -436,6 +436,7 @@ async def benchmark_generative_text(
         backend=backend,
         profile=profile,
         environment=NonDistributedEnvironment(),
+        data=args.data,
         progress=progress,
         sample_requests=args.sample_requests,
         warmup=args.warmup,

src/guidellm/benchmark/output.py

@@ -649,6 +649,8 @@ def _get_benchmark_status_metrics_stats(
         status_dist_summary: StatusDistributionSummary = getattr(
             benchmark.metrics, metric
         )
+        if not hasattr(status_dist_summary, status):
+            return [], []
         dist_summary: DistributionSummary = getattr(status_dist_summary, status)
 
         headers = [
@@ -688,7 +690,7 @@ def _get_benchmark_extras_headers_and_values(
         values: list[str] = [
             benchmark.benchmarker.profile.model_dump_json(),
             json.dumps(benchmark.benchmarker.backend),
-            json.dumps(benchmark.benchmarker.requests["attributes"]["data"]),
+            json.dumps(benchmark.benchmarker.requests["data"]),
         ]
 
         if len(headers) != len(values):

src/guidellm/benchmark/schemas.py

@@ -1674,6 +1674,7 @@ def compile(
         environment: Environment,
         strategy: SchedulingStrategy,
         constraints: dict[str, dict[str, Any]],
+        data: list[Any],
     ) -> GenerativeBenchmark:
         """
         Compile final generative benchmark from accumulated state.
@@ -1702,7 +1703,7 @@ def compile(
             ),
             benchmarker=BenchmarkerDict(
                 profile=profile,
-                requests=InfoMixin.extract_from_obj(requests),
+                requests={"data": data},
                 backend=backend.info,
                 environment=environment.info,
             ),