feat: enhance pattern handling

[filipchristiansen]

Enhance pattern handling

• Respect order of include / exclude patterns (process sequentially instead of with sets) so rules like !*.tmp work deterministically.
• Allow projects to override DEFAULT_IGNORE_PATTERNS.
• Add docs for the .gitingestignore file.
• feat: add suggested exclude-pattern picker with usage-based ordering #112
• docs: clarify directory-pattern semantics and update tests #122
• feat: allow include and exclude patterns to be used at the same time #168
• feat: ignore build wrappers #287
• feat(ui): make exclude/include pattern field easier to read & edit #302
• feat(ui): reset include/exclude field when switching selection #317
• bug: .gitignore is ignored, so my file is not ignored #391