docs(tasks): close gaps between OSS and managed Tasks documentation

[sanjay-saxena]

Summary

Review the OSS NVIDIA Cloud Tasks documentation against the managed-environment Tasks documentation and close applicable content gaps for self-hosted NVCF users.

Documentation to review

OSS documentation:

• https://docs.nvidia.com/nvcf/task-creation
• https://docs.nvidia.com/nvcf/container-based-task-creation
• https://docs.nvidia.com/nvcf/helm-based-task-creation

Managed-environment comparison source (internal):

• https://cloud-functions-tme.gitlab-master-pages.nvidia.com/documentation/legacy/latest/tasks.html

Scope

• Identify useful Tasks concepts, workflows, field descriptions, defaults, lifecycle/status information, examples, and operational guidance present in the managed documentation but missing or incomplete in the OSS documentation.
• Add only content that applies to the OSS/self-hosted environment.
• Clearly document intentional behavioral or capability differences instead of copying managed-only behavior.
• Review the Tasks overview, container-based Tasks, and Helm-based Tasks together so terminology and cross-links remain consistent.
• Validate API and CLI examples against the current OSS implementation and nvcf-cli.
• Preserve existing OSS-specific guidance, including authentication and result-handling limitations.

Areas to evaluate include:

• Task creation prerequisites and authentication
• Container and Helm task configuration
• GPU, instance type, backend, and cluster selection
• Arguments, environment variables, secrets, models, and resources
• Runtime, queue, termination, lifecycle, and terminal statuses
• Result handling and retrieval
• Monitoring, events, cancellation, deletion, and troubleshooting

Acceptance criteria

• Applicable gaps across all three OSS Tasks pages are documented.
• Managed-only capabilities are omitted or explicitly identified as unsupported in OSS.
• Examples use current OSS API fields and CLI syntax.
• Terminology, defaults, links, and examples are consistent across the three pages.
• The resulting PR description and public documentation do not link to the internal managed-environment documentation.
• Documentation formatting and link checks pass.