Adds src/__factories__/<entity>.factory.ts to auth, blog, marketing-pages,
navigation, media. Each factory uses defineFactory from @repo/core-testing
with stable date defaults (2026-01-01) so snapshot diffs reflect SUT
behavior only. Refactors mechanical inline-fixture tests to use factories.
Also adds vitest.config.ts and tsconfig path alias to @repo/media (lacked
both), and adds @repo/core-testing devDependency to @repo/media.
Spec: §5.1, §6.3
Aligns tooling packages with the core-* naming convention used by all
other foundation packages (core-shared, core-cms, core-api, core-trpc,
core-ui). Updates ~50 files: package.json names, devDependencies,
tsconfig extends, eslint.config imports, vitest.config imports, AGENTS.md
references, and the boundaries plugin patterns to match the new paths.
The tooling-specific patterns in boundaries/elements are now ordered BEFORE
the broader core-* pattern to ensure correct first-match-wins behavior.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>