[#409] TVS authentication test setup

[marlonbaeten]

Closes #409

Note: this code was co-authored by Claude Opus 4.7
This code should be reviewed and tested by at least 2 other developers.

DOD checklist

For PR maintainer

Perform these checks before marking the PR as ready:

• I have linked the PR to at least one issue.
• I assigned the PR to myself.
• I have added a description how to test this PR (see "Review Instructions").
• I have added documentation where necessary.

For reviewer

• I have read all code changes.
• I have audited the code quality.
• I have tested the changes either or both:
  • locally
  • on the test environment (preferred)
• I have validated that the PR is functionally correct (use-cases, figma designs, etc.)

Review instructions

Login locally with the TVS mock service. Validate that picking a different BSN gives different data and vice-versa.

[github-actions]

Sigrid maintainability feedback

✅ You wrote maintainable code and achieved your objective of 3.5 stars.

Show details

Sigrid compared your code against the baseline of 2026-05-04.

👍 What went well?

You fixed or improved 1 refactoring candidates.

Risk	System property	Location
🟡	Unit Size (Fixed)	src/state.rs AppState.on_authenticated(CookieJar,HeaderMap)

👎 What could be better?

Unfortunately, 7 refactoring candidates were introduced or got worse.

Risk	System property	Location
🔴	Unit Size (Worsened)	src/error/response.rs ErrorResponse.from_app_error(AppError)
🟠	Unit Size (Worsened)	src/error/app_error.rs AppError.fmt(Formatter<'_>)
🟡	Unit Size (Introduced)	src/state.rs AppState.on_authenticated(Claims,CookieJar,HeaderMap)
🟡	Unit Size (Introduced)	src/state.rs AppState.new_with_config(Config)
🟡	Unit Size (Introduced)	src/auth/session_db.rs session_from_row(SessionRow)
🟡	Unit Interfacing (Introduced)	src/state.rs AppState.on_authenticated(Claims,CookieJar,HeaderMap)
🟡	Module Coupling (Worsened)	src/auth/session.rs

📚 Remaining technical debt

4 refactoring candidates didn't get better or worse, but are still present in the code you touched.

View this system in Sigrid to explore your technical debt

⭐️ Sigrid ratings

System property	System on 2026-05-04	Before changes	New/changed code
Volume	N/A	N/A	N/A
Duplication	4.7	5.5	5.5
Unit Size	3.0	2.9	2.9
Unit Complexity	4.2	5.5	5.5
Unit Interfacing	2.3	4.4	3.8
Module Coupling	3.7	2.7	2.8
Component Independence	2.5	N/A	N/A
Component Entanglement	2.1	N/A	N/A
Maintainability	3.3	3.9	3.9

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[github-actions]

PDF diff summary

Template	Input	Status
model-h1.typ	model-h1-example-1.json	🔵 identical
model-h1.typ	model-h1-example-2.json	🔵 identical
model-h1.typ	model-h1-example-3.json	🔵 identical
model-h3-1.typ	model-h3-1-example-1.json	🔵 identical
model-h3-1.typ	model-h3-1-example-2.json	🔵 identical
model-h3-1.typ	model-h3-1-example-3.json	🔵 identical
model-h4.typ	model-h4-example-1.json	🔵 identical
model-h4.typ	model-h4-example-2.json	🔵 identical
model-h4.typ	model-h4-example-3.json	🔵 identical
model-h9.typ	model-h9-example-1.json	🔵 identical
model-h9.typ	model-h9-example-2.json	🔵 identical
model-h9.typ	model-h9-example-3.json	🔵 identical

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.8% Duplication on New Code

See analysis details on SonarQube Cloud