Track ESLint 10 upgrade compatibility with Nx

[cursor]

Problem

The dependency upgrade work left ESLint at 9.39.2 because upgrading to ESLint 10 currently breaks lint execution in this repository.

Observed failure during trial upgrade in root, packages/workshop-app, and example:

• npm run lint fails in Nx lint target with: ESLint is not a constructor

Proposal

• Keep ESLint pinned to 9.x for now.
• Revisit ESLint 10 once the Nx ESLint integration used by this repo supports it.
• Retest with full validation (npm run lint, npm run validate, and CI).

Acceptance Criteria

• Nx lint target runs successfully with ESLint 10.
• npm run validate passes with ESLint 10.
• CI validate workflow passes on an ESLint 10 upgrade PR.
• Dependency manifests and lockfiles are updated to ESLint 10 where applicable.

Note

A prior tracking issue was created with malformed body content due shell escaping; this issue is the clean replacement.