fix(pixel-agent-teams): validate index range in worker constructor

[Vishaaallll]

Why this matters

In ods/extensions/services/dashboard-api/pixel_agent_teams.py, worker(team_id, index, role) assigns "id": str(index) without checking whether index is within the valid team agent bounds 0..5. Supplying out-of-range numbers, booleans, or strings produces malformed child worker records and violates router pattern constraints Field(pattern=r"^[0-5]$").

This surgical fix validates that index is strictly an int between 0 and 5, raising ValueError on invalid index arguments.

Validation

• Baseline reproduction: verified that worker(id, -1, "builder") was admitted on baseline.
• Post-fix behavior: raises ValueError("index must be an integer between 0 and 5").
• Telemetry: pixel-teams suite: 2 passed. New-test syntax and diff checks pass; new regression wired into Linux CI.

Overlap check

Inspected open/closed PRs. PR #5734 validated roles_for counts; zero overlap with worker index parameter validation.

Risk / AI disclosure

AI-assisted investigation, patch, and regression tests. Strengthens agent worker boundary checks. Independent review remains a gate.

Follow-up integration evidence

Composed locally with public-beta at 4fa6ad170 without conflicts. CI and unit checks pass.

[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.