app: AGENTS.md: docs: Add app/ development documentation and linting/formatting scripts

[illume]

Summary

Adds developer documentation and npm script wrappers for the desktop app to improve contributor experience and align with existing frontend/backend patterns.

Helps agents that get stuck when doing stuff in the app folder because they don't know how to lint/format/etc.

Changes

• frontend: .eslintignore: .prettierignore: Ignore app .js files
• package.json: app: Add format, lint and lint-fix scripts
• docs/development/app.md: Add basic app developer guide
• AGENTS.md: Add app/ folder development notes

Steps to Test

1. Run npm run app:lint - should lint app TypeScript without errors
2. Run npm run app:format - should format app TypeScript files
3. Run npm run app:lint:fix - should fix auto-fixable issues
4. Run root npm run lint - should include backend, frontend, and app
5. Run git status after npm run app:build and it should not show any files.
6. Run npm run app:lint after npm run app:build and it should not show any errors.

[Copilot]

Pull request overview

This PR adds developer documentation and npm script wrappers for the desktop app to improve the contributor experience, particularly for AI agents working in the app folder. It provides consistent linting, formatting, and testing commands similar to frontend and backend workflows.

Changes:

• Added npm script wrappers in root and app package.json for format, lint, and lint-fix operations
• Updated ESLint and Prettier ignore files to exclude compiled JavaScript files from the app folder
• Created comprehensive app development documentation at docs/development/app.md

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
package.json	Added app:format, app:lint, and app:lint:fix scripts; integrated app linting into root lint commands
app/package.json	Added format, lint, and lint-fix scripts that delegate to frontend scripts
frontend/.eslintignore	Simplified to use wildcard pattern for app electron .js files
frontend/.prettierignore	Added ignore pattern for compiled app JavaScript files
docs/development/app.md	New comprehensive development guide covering build, lint, format, test, and packaging workflows
AGENTS.md	Updated with app development documentation references and new example workflow

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[joaquimrocha]

/lgtm
/approve

Thanks @illume !

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: illume, joaquimrocha

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• OWNERS [illume,joaquimrocha]

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[illume]

Thanks for the review @joaquimrocha