Misc updates for making CSP headers work

[bheesham]

Turns out the ingress controller was not acting on the nginx.ingress.kubernetes.io/configuration-snippet annotation because we didn't configure it to (or perhaps the defaults changed).

This also sets up some rules to deal with mozilla-iam/dino-park-front-end#716.

Jira: IAM-1775

[Copilot]

Pull Request Overview

This PR updates CSP (Content Security Policy) headers configuration to work with the ingress controller by enabling snippet annotations and restructuring security header implementation.

• Enables snippet annotations in the ingress controller configuration
• Restructures CSP headers from a single line to multiple separate header directives
• Removes public/private environment conditional logic and related routing rules

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
k8s/values/test.yaml	Removes public flag from test environment configuration
k8s/values.yaml	Removes public flag from default values
k8s/templates/router.yaml	Removes conditional public routing logic
k8s/templates/public-splitter.yaml	Updates location patterns and removes CSP header, simplifies logout redirect logic
k8s/templates/ingress.yaml	Restructures CSP and security headers from single line to multiple separate directives
k8s/templates/ingress-controller.yaml	Enables snippet annotations and adds events RBAC permissions

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