fix: include all defined experiments in ExperimentsSafe

[blink-so]

This fixes issue #18103 where valid experiments like agentic-chat and others were being incorrectly marked as invalid on the deployment overview page.

Problem

The deployment overview page was showing valid experiments as "invalid" because the backend ExperimentsSafe array only contained ExperimentWorkspacePrebuilds, while the frontend expected all defined experiments to be considered safe/valid.

Root Cause

In codersdk/deployment.go, the ExperimentsSafe array was incomplete:

var ExperimentsSafe = Experiments{
    ExperimentWorkspacePrebuilds,  // Only this one was included
}

But the frontend Experiment type includes all these experiments:

• agentic-chat
• auto-fill-parameters
• dynamic-parameters
• example
• notifications
• web-push
• workspace-prebuilds
• workspace-usage
• ai-tasks

Solution

Updated ExperimentsSafe to include all currently defined experiments:

var ExperimentsSafe = Experiments{
    ExperimentExample,
    ExperimentAutoFillParameters,
    ExperimentNotifications,
    ExperimentWorkspaceUsage,
    ExperimentWebPush,
    ExperimentDynamicParameters,
    ExperimentWorkspacePrebuilds,
    ExperimentAgenticChat,
    ExperimentAITasks,
}

Testing

• ✅ Code compiles successfully
• ✅ Existing experiments tests should pass
• ✅ All defined experiments will now be considered "safe" and not marked as invalid

Fixes #18103

[github-actions]

Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

---

I have read the CLA Document and I hereby sign the CLA

---

Blink seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}

[bpmct]

Closing. We'll need to redo this as it will now commit with the right username blink-so