fix: dependency updates compatibility & code refactoring

[this-is-tobi]

Description

This PR addresses several issues introduced by dependency updates and includes a minor code refactoring:

1. CI not failing on VitePress build errors — the build command was catching errors and logging them but exiting with code 0, so dead links and other VitePress build failures were silently swallowed in CI/CD pipelines. Added process.exit(1) in the catch block.

2. Lint errors after @antfu/eslint-config update — the new e18e/prefer-static-regex rule requires regex literals to be declared at module scope rather than inline. Moved all inline regex literals to module-scope constants across src/utils/regex.ts, src/utils/functions.ts, public/templates/theme/index.ts, and vite.config.ts.

3. Test failures after vitest v4 update — vitest v4 changed how new mockFn() works: it now calls new implementation() internally, which fails for arrow functions. Updated Octokit constructor mocks in git.spec.ts to use regular function expressions. Also fixed a pre-existing bug where writeFileSync was called with a spread string ([...str1, ...str2]), which produced character arrays instead of concatenated strings.

4. Regex centralisation refactoring — moved all regex constants into src/utils/regex.ts (pure constants, no fs logic) and moved replaceRelativePath / replaceReadmePath functions into src/utils/functions.ts to better separate concerns.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Other (please describe): dependency updates compatibility + code refactoring

How Has This Been Tested?

All existing unit tests were updated to reflect the changes and pass locally.

Test Configuration:

• Node.js: 24.14.0
• pnpm: 10.32.0
• vitest: 4.0.18

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[github-actions]

🤖 Hey !

The security scan report for the current pull request is available here.