story/FCT2-20672- text content update for the unauthorised page

[renjithabby]

https://cpsgovuk.atlassian.net/browse/FCT2-20672

PR checklist

Tick what applies before you raise. Delete anything that doesn't.

Correctness

• Does what the ticket asks for
• Handles the edge cases (empty, null, zero, large inputs), not just the happy path
• Errors are handled, not swallowed
• New logic has tests, including the failure cases
• Tests assert something real, not just run the code

Keeping it simple

• Doesn't rebuild something that already exists in the codebase
• No more complex or slower than it needs to be
• No leftover debug logging or commented-out code

Code Quality

• Pre-commit hooks were run for all commits in this PR

Easy to miss (a green pipeline won't flag these)

• One logical change, not a pile of unrelated stuff

If you touched the UI

• API changes are reflected in the MSW handlers in src/mocks and the matching zod schema, so the mocked tests aren't passing against a contract that's gone
• New config or feature flags are wired into the VITE build variables, not just added in code
• Data fetches handle the loading, empty and error states, not just success, and match how the rest of the app already does it
• Ran prettier (npm run prettier:format), since CI lints but doesn't check formatting
• Checked accessibility (keyboard nav, screen reader, sensible labels), since the Lighthouse run is manual and won't flag it for you

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues
0 New dependency risks

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarQube Cloud