Respect custom appDir for route config

[Aeternologist]

Description

The plugin now correctly respects the configured appDir instead of assuming the default ./app. This ensures route discovery and “open in editor” features work when users place their app in a custom directory.

Fixes # (issue)

Replaced hardcoded "./app/routes.ts" with appDir, "routes.ts")
Passed appDir through to route generation flows:
handleWriteFile({ ..., appDir })

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Manual verification:

• Configured the plugin with a custom app dir in vite.config.ts:
  reactRouterDevTools({ appDir: "./src/app" })

• Ensured src/app/root.tsx and src/app/routes/test.tsx exist and defined routes.

• Routes appear in the devtools Routes panel.
  “Add route” generates a file under ./src/app/routes/... and opens it in the editor.

• Unit tests

Checklist:

• My code follows the guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/forge-42/react-router-devtools@213

commit: ecf701e