[44/44] Enable TS strict mode in dotcms-ui

Description

Part of the strict-mode rollout epic #35932. Enable TypeScript strict mode for the dotcms-ui project using typescript-strict-plugin.

• Dependency layer: 10 (0 = leaf library, 10 = top-level app)
• Internal dependents: 1 project(s)
• Rollout order: 44 / 44
• Note: Main admin app - consumes 25 projects; do this last.

All internal dependencies of dotcms-ui should already be in strict mode before starting (they appear earlier in the rollout order).

Acceptance Criteria

• dotcms-ui's src is added to the typescript-strict-plugin strict paths config.
• All resulting type errors are resolved (no new any; use explicit types).
• // @ts-strict-ignore is used only where unavoidable, each with a follow-up TODO.
• yarn nx run dotcms-ui:lint passes (and :build / :test where applicable).
• npx tsc-strict passes for dotcms-ui.
• yarn nx affected -t build does not break dependents.

Priority

Medium

Additional Context

One project in the bottom-up rollout tracked by epic #35932. Depends on the bootstrap task being merged and on lower-layer projects already being strict.

Start by locating the dotcms-ui project configuration and the typescript-strict-plugin strict paths setup, then inspect its src for errors after enabling the project. Run npx tsc-strict and yarn nx run dotcms-ui:lint, followed by the applicable build and test targets. Done means the listed checks pass, unavoidable ignores have follow-up TODOs, and affected dependents still build.