feat(web): expose output directory name in Eval/Perf task forms

[Dhru1001]

Lets users name a run's output directory from the Tasks tab instead of relying on the auto-generated timestamp id. The name becomes the task id (sanitized to filesystem/header-safe characters), which is what the backend already uses to derive work_dir, progress tracking, log lookup, resume, and report listing -- so no backend changes are needed and none of those flows break.

[Dhru1001]

@Yunnglin

[Yunnglin]

Thanks for adding this. The user need is reasonable, but the implementation should reuse EvalScope’s existing output configuration instead of turning the directory name into task_id.

EvalScope already has TaskConfig.work_dir / no_timestamp for Eval and outputs_dir / name / no_timestamp for Perf. Please pass the setting through the normal config contract and let the service resolve it safely under EVALSCOPE_OUTPUT_DIR.

task_id must remain independently unique because it identifies processes, progress, logs, reports, and stop operations. With the current stable name -> task_id mapping:

• running the same Perf name twice fails because benchmark_data.db already exists;
• concurrent same-name tasks overwrite the same process-registry entry and share one output directory.

Please separate the user-facing output/run name from the unique task ID, define collision/resume behavior explicitly, and add coverage for repeated names, concurrent submissions, Perf reruns, Unicode names, and path traversal. If this is only for readability, the simplest solution is a readable name plus a unique suffix.