v0.4.0

Phase 3: 17 new components + 4 hooks

Phase 3A — Layout & Navigation

• ScrollArea — scrollable region with visible scrollbar and keyboard navigation
• Tabs — tab panels with underline/boxed/pills variants, badge counts, disabled tabs
• Accordion — expand/collapse sections, single or multiple open
• Panel — added SplitPane component for flex-ratio split layouts

Phase 3B — AI-Era Components

• StreamingText — token-by-token LLM output with blinking cursor
• TokenCounter — token budget bar with green→yellow→red thresholds
• CodeBlock — syntax highlighting for 13 languages, no external deps
• DiffView — unified diff viewer using a built-in LCS algorithm
• Typewriter — character-by-character text animation

Phase 3C — Data & Power

• TreeView — collapsible tree with vim-style keyboard navigation
• Autocomplete — live-filter input with dropdown, Tab-to-complete
• Stepper — multi-step wizard progress indicator
• DataTable — sort, filter, paginate, row selection
• Gauge — metric bar with configurable color thresholds
• Sparkline — inline ▁▂▃▄▅▆▇█ mini chart
• Markdown — terminal Markdown renderer
• JSONViewer — interactive JSON explorer with expand/collapse

Phase 3D — Hooks

• useFocusManager — register/unregister focus regions
• useKeyBindings — declarative key binding map
• useTerminalSize — live terminal columns/rows with resize tracking
• useAsync — async data fetching with loading/data/error state

Fixes

• Fixed RangeError: Invalid count value crash in TokenCounter preview
• Stripped ANSI codes in CodeBlock tests for CI compatibility
• Bumped all version badges to v0.4.0 across docs site