4239: UI legacy header nav and dashboard base background updates like EM.

[DaisyGuti]

Ticket

Resolves #4239 Part of Parent #3825

Changes

• UI updates to nav bar to make legacy look like the Enterprise Mode version
• UI updates to the background so it is the light gray

Context for reviewers

https://cisa-corp.slack.com/archives/C05BGB4L5NF/p1759239519393089

Setup

1. Login to https://getgov-potato.app.cloud.gov/admin
2. Remove yourself from all portfolios so you can see the legacy only view
3. Legacy view should look like the new portfolio view (compare against staging with portfolio permissions OR re-add your portfolio permissions and refresh the page)

Code Review Verification Steps

As the original developer, I have

Satisfied acceptance criteria and met development standards

• Met the acceptance criteria, or will meet them in a subsequent PR
• Created/modified automated tests
• Update documentation in READMEs and/or onboarding guide

Ensured code standards are met (Original Developer)

• If any updated dependencies on Pipfile, also update dependencies in requirements.txt.
• Interactions with external systems are wrapped in try/except
• Error handling exists for unusual or missing values

Validated user-facing changes (if applicable)

• Follow the process for requesting a design review. If code is not user-facing, delete design reviewer checklist
• Verify new pages have been added to .pa11yci file so that they will be tested with our automated accessibility testing
• Checked keyboard navigability
• Tested general usability, landmarks, page header structure, and links with a screen reader (such as Voiceover or ANDI)

As a code reviewer, I have

Reviewed, tested, and left feedback about the changes

• Pulled this branch locally and tested it
• Verified code meets all checks above. Address any checks that are not satisfied
• Reviewed this code and left comments. Indicate if comments must be addressed before code is merged
• Checked that all code is adequately covered by tests
• Verify migrations are valid and do not conflict with existing migrations

Validated user-facing changes as a developer

Note: Multiple code reviewers can share the checklists above, a second reviewer should not make a duplicate checklist. All checks should be checked before approving, even those labeled N/A.

• New pages have been added to .pa11yci file so that they will be tested with our automated accessibility testing
• Checked keyboard navigability
• Meets all designs and user flows provided by design/product
• Tested general usability, landmarks, page header structure, and links with a screen reader (such as Voiceover or ANDI)
• (Rarely needed) Tested as both an analyst and applicant user

As a designer reviewer, I have

Verified that the changes match the design intention

• Checked that the design translated visually
• Checked behavior. Comment any found issues or broken flows.
• Checked different states (empty, one, some, error)
• Checked for landmarks, page heading structure, and links

Validated user-facing changes as a designer

• Checked keyboard navigability
• Tested general usability, landmarks, page header structure, and links with a screen reader (such as Voiceover or ANDI)
• Tested with multiple browsers (check off which ones were used)
  • Chrome
  • Microsoft Edge
  • FireFox
  • Safari
• (Rarely needed) Tested as both an analyst and applicant user

References

• Code review best practices

Screenshots

[github-actions]

🥳 Successfully deployed to developer sandbox potato.

[github-actions]

🥳 Successfully deployed to developer sandbox potato.