[TAO-0000][Chore] Add experimental decorator to tao-deploy

[vpraveen-nv]

What changes are proposed in this pull request?

Adds the experimental decorator to nvidia_tao_deploy/cv/common/decorators.py (alongside monitor_status, override, subclass), matching the existing implementation in tao-pytorch/nvidia_tao_pytorch/core/decorators/experimental.py.

from nvidia_tao_deploy.cv.common.decorators import experimental

@experimental("This feature is under active development")
def my_new_function():
    ...

@experimental
class MyExperimentalClass:
    ...

Why are the changes needed?

Parity with tao-pytorch: deploy-side experimental APIs should carry the same yellow-highlighted UserWarning so users know they are invoking an experimental surface.

Related issues

N/A

Does this PR introduce any user-facing change?

Yes — decorated APIs now emit a UserWarning when invoked; no existing behavior changes.

How was this patch tested?

Verified the decorator emits the expected warning for both function and class usage, mirroring the tao-pytorch implementation and its existing coverage. No new tests added — the implementation is copied verbatim from the already-tested tao-pytorch version.

Was this patch authored or co-authored using generative AI tooling?

Generated-by: Claude Code

Release note

Added an experimental decorator that warns users when invoking experimental tao-deploy APIs.

Checklist

• My commits are signed off per the DCO (git commit -s) — see CONTRIBUTING.md
• I have read the contributing guidelines
• The code follows the project's style, and lint and format checks pass locally
• I added or updated tests covering this change
• All tests pass locally
• I added or updated documentation (README, docstrings, docs pages, examples)
• I updated the version, changelog, or migration notes if this change requires it
• If this touches components that are optional to install, the imports are guarded
  so the package still works without them (reviewers: please verify this)
• No secrets, credentials, proprietary data, or customer data are included in this PR
• I understand this contribution is licensed under the repository's license, and that
  my commit author name and email become permanently public once merged

Notes for reviewers

Originally targeted release/7.1.0 on GitLab; rebased and retargeted to main during the GitHub migration. Adds colorama/termcolor deps — check they're in the deploy container requirements.

---

Migrated from GitLab MR nvidia-tao-toolkit/tao-deploy!209, rebased onto GitHub main.

[tao-pr-bot]

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