feat(cz): add conditional scope requirements based on file patterns

[vabatta]

Problem

Currently require-scope is a binary setting - scopes are either always required or always optional. This doesn't accommodate workflows where:

• Service/package changes should require a scope (for changelog generation)
• Root config files or CI changes could be scopeless (trivial maintenance)

Use Case

In a monorepo with release-please generating per-service changelogs, we want:

feat(teams-mcp): add feature    # Required - goes to teams-mcp changelog
chore: update deps              # Allowed - root files only, no changelog impact
chore: fix workflow             # Allowed - .github/** only, no changelog impact
feat: new feature               # BLOCKED - touching services without scope corrupts changelogs

Proposed Solution

Add a new setting like require-scope-unless-patterns:

[settings]
require-scope = true
require-scope-unless-patterns = *, .*, .github/**

Behavior:

• Scope is required by default (require-scope = true)
• BUT if ALL files match require-scope-unless-patterns, scope becomes optional
• If ANY file doesn't match the exception patterns, scope is required

Alternative Syntax Options

# Option A: Explicit exception patterns
require-scope-unless-patterns = *, .*, .github/**

# Option B: Reference existing scopes
require-scope-unless-scopes = main, ci

# Option C: Invert - define which patterns require scope
require-scope-for-patterns = services/**, packages/**

Current Workaround

Set require-scope = false and rely on team discipline + code review. This is error-prone for changelog-sensitive repositories.