- add `removeAllMarks` function to inline/types.js
- implement `applyRemoveAllMarks` handler in BlockEditor client
- add `TextClearIcon` button with separator in Toolbar component
- expose `onClearMarks` prop on InlineToolbar
- update README to document new clear formatting action
- update blockRegistry to accept ReactNode icons instead of emoji strings
- replace emoji icons in all built-in block types with icon components from shared icons
- add `isHexColor` and `collectUsedColors` helpers to inline/types.js
- extend `color` and `highlight` marks to accept hex color strings in addition to palette keys
- pass `usedColors` (collected from document) to InlineToolbar
- update InlineToolbar color popover to show used colors and a free color input
- add new icons to shared icons index
- update README to reflect icon, color, and toolbar popover changes
- migrate block content from plain strings to InlineNode[] structure
- add inline toolbar (bold, italic, code, color, link) on text selection
- add checklist block type with toggle support
- add image block type (URL-based, phase 2)
- add inline serialization helpers (inlineToDom, domToInline)
- add inline types and length utilities
- extend caret utils with range get/set support
- update block registry and all existing block types for new content model
- update demo blocks in ComponentsPage to use rich inline content
- update README to reflect new architecture
- swap PlusSignIcon for Add01Icon in Block.client.js add button
- remove PlusSignIcon export from shared icons index
- update README to reflect renamed icon
- replace `+` and `⋮⋮` text with `PlusSignIcon` and `DragDropVerticalIcon` components
- add `Add01Icon` export to shared icons index
- update README to reference icon names and link to icons source
- add `isSelected` prop and overlay highlight to Block component
- implement double ctrl+a: first selects block content, second selects all blocks
- add `onSelectAllBlocks` callback prop to Block
- add `selectedBlockIds` state and `selectAllBlocks`/`deleteSelectedBlocks` helpers in BlockEditor
- detect cross-block native selection via `selectionchange` and convert to block selection
- handle backspace/delete key to remove all selected blocks
- clear block selection on click outside or focus change
- update README to document multi-block selection behaviour
- export new icons used by the feature