Summary

• Adds an entry option to control which files get .d.ts generation using glob patterns (powered by picomatch)
• When entry is specified, only matching files emit .d.ts chunks — even non-Rolldown entries
• Supports negation patterns for exclusion (e.g., ['**', '!src/icons/**'])
• Patterns are matched against file paths relative to cwd

Closes #28, closes #212

Test plan

• Added test for include glob filtering (entry: 'input1.ts')
• Added test for negation glob (entry: ['**/*.ts', '!input2.ts'])
• All 196 existing tests pass
• Typecheck passes