v0.4.1

Changelog

• d10cf0e feat(pulse): add timeline annotations and event markers with sliding cards
• 3615a50 fix(pulse): normalize inverted range in SetRange and define DefaultEventColor
• 7d7bbf5 perf(pulse): eliminate redundant series data copying and optimize grid allocations
• 4baf721 refactor(pulse): decompose monolithic pulse.go into cohesive domain modules
• d596d73 refactor(pulse): split monolithic test file into domain test suites
• 7e864f9 refactor(pulse): unify event marker and guideline rendering into shared helpers
• 7914c99 test(pulse): add benchmark suite for rendering and sliding window operations