## What does this PR do?
Adds a welcome modal for new organizations that appears after organization creation. The modal showcases key features of the Organizations plan and provides a better onboarding experience.
## Visual Demo (For contributors especially)
#### Image Demo:
## Mandatory Tasks (DO NOT REMOVE)
- [x] I have self-reviewed the code.
- [x] I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A
- [x] I confirm automated tests are in place that prove my fix is effective or that my feature works.
## How should this be tested?
1. Create a new organization through either:
- The onboarding flow
- The settings/organizations/new page
- The organization creation form
2. After successful creation and redirect, verify the welcome modal appears showing organization features.
3. Verify the modal can be closed by:
- Clicking the "Continue" button
- Clicking outside the modal
- Pressing ESC key
4. Verify the modal doesn't reappear after being closed (query param and session storage should be cleared).
## Checklist
- I have read the [contributing guide](https://github.com/calcom/cal.com/blob/main/CONTRIBUTING.md)
- My code follows the style guidelines of this project
- I have commented my code, particularly in hard-to-understand areas
- I have checked if my changes generate no new warnings
