Add Knip to lint script for dead code detection

[Copilot]

Integrates Knip into the lint workflow to automatically detect unused files, dependencies, exports, and duplicate exports across the monorepo.

Changes

• Added Knip v5.73.1 as devDependency
• Created knip.json with workspace-specific configuration:
  • Entry points for root scripts, jaeger-ui (Vite), and plexus (Webpack)
  • Ignore patterns for demo directories
  • Explicit ignore for indirect dependencies (@tanstack/react-virtual, react-side-effect)
• Integrated into npm run lint via npm-run-all (runs in parallel with existing linters)
• Updated documentation (README.md, AGENTS.md) to reflect new lint step

What Knip Detects

• Unused files and dependencies
• Unlisted dependencies
• Unused/duplicate exports
• Dead TypeScript types and enum members

Auto-detected Plugins

TypeScript, React, Vite, Webpack, Jest, Babel, ESLint, Prettier, GitHub Actions, husky, lint-staged

Usage

# Full lint (includes Knip)
npm run lint

# Knip only
npm run knip

# Filter by issue type
npm run knip -- --include files
npm run knip -- --include dependencies

The lint script now fails when dead code is detected, enforcing a cleaner codebase.

Original prompt

I would like to add a step to the npm run lint script that would run Knip to detect and report dead code. Knip should be configured with plugins relevant to this repository,

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.89%. Comparing base (60b5118) to head (c3acf11).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3208      +/-   ##
==========================================
- Coverage   97.89%   97.89%   -0.01%     
==========================================
  Files         262      261       -1     
  Lines        8214     8209       -5     
  Branches     2087     2173      +86     
==========================================
- Hits         8041     8036       -5     
  Misses        172      172              
  Partials        1        1              

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[Parship12]

should it immediately stop merge if it find unused code, or should we first run it in the background without blocking PRs?