chore: align feature branch with develop and fix route/test references

[biancode]

Context

develop has advanced and introduces changes that affect this feature branch integration (including route/file references and documentation overlap).

Goal

Create a tracked task so the upcoming PR can reference a concrete issue and close it when complete.

Scope

• merge latest develop into feature/design_analyse
• resolve follow-up mismatches introduced by src/app.html -> src/index.html
• update root redirect and test targets to current entry file
• align hash route expectations in Playwright tests (#formular vs #forms)
• re-check documentation consistency after merge

Acceptance Criteria

• branch contains latest develop
• app entry path works from root redirect
• Playwright specs use current routes/paths and run as expected
• docs remain consistent with implemented behavior
• PR references this issue and closes it

PR Reference

Use in PR description:

• Closes #