Set up Renovate and Knip

[NTCoding]

Deliverable: Automated dependency updates and dead code detection

Context

The monorepo currently lacks:

• Automated dependency update tooling (dependencies go stale)
• Unused code detection (dead code accumulates)

Delivers

1. Renovate configuration (renovate.json) at repo root - use GitHub Renovate App
2. Knip configuration (knip.json or knip.ts) at repo root
3. Knip integrated into verify gate

Acceptance Criteria

• Given Renovate is configured, When a dependency has updates, Then Renovate creates a PR automatically
• Given Knip is configured, When unused exports/dependencies exist, Then Knip reports them
• Given Knip is in CI, When verify runs, Then unused code violations fail the build

Related Code

• /package.json
• /apps/*/package.json
• /packages/*/package.json

Migrated from Task Master #68