fix(pixel-gateway): validate top_p probability bounds in runtime gateway

[vaibhavsrv]

Why this matters

In ods/bin/pixel_provider/runtime_gateway.py, the validate_request routine admits the optional top_p parameter without type or probability boundary enforcement. When external clients supply non-numeric values (such as strings or booleans) or numeric values outside the standard probability range $[0.0, 1.0]$ (e.g., negative floats or values $> 1.0$), the request bypasses admission validation and triggers downstream model runner exceptions or unpredictable token nucleus sampling.

This change surgically adds bounds and type verification for top_p in validate_request, rejecting invalid types and values outside $[0.0, 1.0]$ with invalid-inference-request. Valid probabilities, integers 0 and 1, and existing inference parameters remain unaffected.

Validation

• Baseline reproduction: Requests specifying top_p: -0.5, top_p: 2.0, or top_p: True passed validate_request without error.
• Post-fix behavior: Requests containing out-of-bounds numbers or non-numeric types raise RuntimeErrorCode('invalid-inference-request'), while valid floats between 0.0 and 1.0 are admitted.
• Telemetry: Pixel gateway suites: 3 passed. New-test Ruff, ShellCheck, and diff checks pass; new regressions wired into Linux CI.

Overlap check

Recent PRs #6328 (snapshot permissions in ods-update.sh), #6326 (argument count validation in ods-restore.sh), and #5715 (top_p parameter validation in pixel-inference) operate on different modules. Specifically, #5715 scoped validation to the FastAPI inference worker, whereas this PR hardens the independent runtime provider gateway in ods/bin/pixel_provider/runtime_gateway.py without overlap.

Risk / AI disclosure

AI-assisted investigation, implementation and CLI regressions. This strengthens an API validation check, not runtime admission. Independent human review and platform/runtime qualification remain gates. No running configuration, deployment or upstream merge changed.

Follow-up integration evidence

Composed with #6328 at 17fe420 without conflicts. Production and test diffs passed together; gateway and runtime checks remain intact.
Backlog composition was local-only (production/test diffs, excluding workflow/Makefile wiring); it is not an upstream merge or independent human approval. Declared live-review gates remain open.

[Lightheartdevs]

Thanks for this contribution. public-beta was promoted into main on 2026-09-24 and no longer receives changes, so we're closing pull requests that target it. This isn't a judgment on the change itself. If it's still needed, please rebase onto main and open a focused PR. See #7253 for details and the contribution policy.