Harden namespace test deployment to satisfy container security context alert

[Copilot]

This PR addresses code scanning alert #90 in the namespace test deployment manifest by replacing a no-op container security context with an explicit hardening control. The change is scoped to the flagged location only.

• Alert-targeted manifest update

  • Updated tilt_modules/namespace/test/deployment.yaml for the busybox container.
  • Replaced empty securityContext with a concrete setting required by the scanner.

• Effective delta

  containers:
    - name: busybox
      image: busybox
      securityContext:
        allowPrivilegeEscalation: false

• Scope

  • No unrelated manifest or application code changes.