fix: add heading tags to B2B org section

[daniellefrappier18]

What are the relevant tickets?

Fixes https://github.com/mitodl/hq/issues/11297

Description (What does it do?)

Adds heading tags to the B2B organization section of the dashboard for screen reader accessibility. This is a follow-up to #3253, which added headings to the My Learning section.

• OrganizationCards (home dashboard): The "As a member of [Org] you have access to:" label is now an h2, and each contract name link is wrapped in an h3, establishing a proper heading hierarchy beneath the page's h1.
• ContractContent (contract detail page): The welcome message title had variant="h5" which rendered as <h5>, skipping heading levels after the org name h1. Fixed to component="h2". The "No programs found" state had an incorrect duplicate h1 and fixed to h2.
• Tests: Added getByRole("heading") assertions to OrganizationCards.test.tsx to verify both the org section and contract name headings are accessible.

Screenshots (if appropriate):

• Desktop screenshots
• Mobile width screenshots

BEFORE Dashboard Page

AFTER Dashboard Page

BEFORE Contact Page

AFTER Contact Page

How can this be tested?

Prerequisites:

1. A local MITx Online instance with a B2B organization and contract configured.
2. In MITx Online admin → B2B → Organizations, create a test org
3. In B2B → Contracts, create a contract linked to that org
4. In B2B → User organizations, add your local user to the org
5. Assign the contract to the user

This change is best verified by inspecting the DOM in browser DevTools:

1. Log into the dashboard as a user who is a member of a B2B organization
2. On the home dashboard, open DevTools → Elements and inspect the org section ("As a member of [Org] you have access to:") — it should be an <h2> element, and each contract name below it should be an <h3>
3. Click into a contract to open the contract detail page and inspect:
4. The org name should be <h1>
5. The welcome message title (if present) should be <h2>

Additional Context

[github-actions]

OpenAPI Changes

No changes detected

View full changelog

Unexpected changes? Ensure your branch is up-to-date with main (consider rebasing).

[Copilot]

Pull request overview

Improves screen reader accessibility on the B2B organization dashboard and contract detail views by introducing proper heading semantics and ensuring a consistent heading hierarchy under the page title.

Changes:

• Dashboard org section: renders the org access label as an h2 and each contract title as an h3.
• Contract detail page: adjusts welcome message and empty-state headings to avoid skipped/duplicate heading levels.
• Adds RTL assertions to ensure the new headings are discoverable via getByRole("heading").

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/OrganizationCards.tsx	Adds h2/h3 semantics for org section label and contract titles.
frontends/main/src/app-pages/DashboardPage/CoursewareDisplay/OrganizationCards.test.tsx	Adds tests asserting org and contract headings are accessible via heading roles.
frontends/main/src/app-pages/DashboardPage/ContractContent.tsx	Fixes heading levels for welcome message and “No programs found” states.