docs: add monorepo management rules

[KJ7LNW]

Context

Add comprehensive documentation for monorepo structure and workflows to help models understand the repository structure better.

Implementation

This PR adds detailed documentation in .roo/rules/monorepo.md that covers:

• Workspace organization and primary development areas
• Package dependency management with pnpm
• Turborepo configuration guidelines
• Test execution strategies for both vitest and jest
• Migration path from deprecated test formats to modern ones

This documentation will help prevent errors in package management and ensure tests are properly created and executed.

@cte Please review these guidelines to ensure they accurately reflect the monorepo structure and best practices.

Fixes: #4295

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Important

Adds .roo/rules/monorepo.md for monorepo management, detailing workspace organization, dependency management, Turborepo configuration, and testing strategies.

• Documentation:
  • Adds .roo/rules/monorepo.md for monorepo management.
  • Covers workspace organization, primary development areas, and package dependency management with pnpm.
  • Provides guidelines for Turborepo configuration.
  • Details test execution strategies for vitest and jest.
  • Describes migration from deprecated .test.ts to .spec.ts formats.
• Testing:
  • Emphasizes using vitest for new tests and migrating failing jest tests to vitest.
  • Specifies file naming conventions for tests: .spec.ts for vitest, .test.ts for jest (deprecated).

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[adamhill]

Any chance we could take a stab at: (since you have broached the subject)

1. Putting the "How to add to Roo's Settings system" doc in here.
2. An .editorconfig
3. Some TS rules we all can live with for patterns and practices, directions we want to move to (like not using jest anymore). Anf maybe a high level description of the project.

[KJ7LNW]

Any chance we could take a stab at: (since you have broached the subject)

1. Putting the "How to add to Roo's Settings system" doc in here.

2. An .editorconfig

3. Some TS rules we all can live with for patterns and practices, directions we want to move to (like not using jest anymore). Anf maybe a high level description of the project.

good idea but I think it should be done as a roo-specific mode. with instructions as part of the role definition that specifically state "use this mode whenever creating new settings in this application". it must be in the role definition not in the custom instructions so that it is visible at all times to the model.

See #4130 for those instructions since they were removed when the docs directory was deleted

[KJ7LNW]

@adamhill is that a pull request you can put together?