Ignore the repository-root .angular build cache directory

Description

An Angular build that starts from the repository root writes its build cache to /.angular/cache instead of /core-web/.angular/cache, and the root path is not ignored. The result is a 60 MB directory with roughly 400 untracked files sitting at the top of a clean checkout.

/core-web/.angular/cache has been ignored since the file was written, and core-web/.gitignore also carries .angular. Neither rule matches the root path, because both are anchored under core-web.

This issue covers the ignore rule only. What makes a build resolve its cache to the repository root instead of the Angular workspace is not yet identified: a cache in the correct location dates from 21 August, the root one first appeared on 16 September, and the Maven path is not responsible (core-web/pom.xml and nodejs-parent/pom.xml both pin workingDirectory to the module's own basedir). That investigation is deliberately out of scope here.

Acceptance Criteria

• /.angular/ is ignored at the repository root
• git status is clean on a checkout that has a root-level .angular directory
• The existing /core-web/.angular/cache rule is left untouched

Priority

Low

Additional Context

The directory holds only regenerable build cache, so deleting it has no consequence.

Inspect the repository-root ignore file alongside core-web/.gitignore, where the existing Angular cache rule is defined. Add the root-level /.angular/ ignore entry without changing the existing /core-web/.angular/cache rule, then verify that git status is clean when a root .angular directory exists.