Implement flexible rich text editor

[max-wells]

Implement rich text editor support for dioxus-ui.

Original request: #43

Living feature plan:
https://github.com/rust-ui/ui/blob/main/plans/PLAN_MINIMAL_EDITOR_FEATURES.md

Plan priorities may evolve during implementation. Contributors should follow the current plan rather than treating the feature table as fixed scope.

Current direction:

• native contenteditable
• Rust/WASM DOM bridge
• no Tiptap/ProseMirror dependency
• demo-first validation on /test-page

Refs #43

[max-wells]

Current plan

Source of truth: PLAN_MINIMAL_EDITOR_FEATURES.md

Priorities may evolve during implementation.

P0 — Core, security, correctness

Feature	Status
Core marks, lists, H1/H2, clear formatting	✅
Initial Markdown → HTML content	✅
Live HTML callback, placeholder, disabled state	✅
Active toolbar state	✅
Typing, caret, selection, undo/redo, IME verification	⚠️
HTML/URL sanitizer tests	⚠️
Safe paste interception	⚠️
SSR/WASM/native verification	⚠️

P1 — Essential rich text

Feature	Status
Inline <code> + separate <pre><code> block	⚠️/❌
Normal paragraph + H1–H6 dropdown	❌
Links insert/edit/remove	❌
Blockquote, horizontal rule, hard break	❌
List nesting/exit behavior	⚠️
Keyboard shortcuts + labels	❌
Accessibility labels/focus	⚠️

P1 — Editor API and UX

Feature	Status
on_focus / on_blur	❌
on_paste / on_keydown / on_selection_change	❌
External content reset	❌
Controlled value mode	❌
Read-only distinct from disabled	❌
Throttled/debounced on_change	❌
Empty paragraph normalization	❌
Enter/Backspace rules	⚠️
Paste as plain text / match style	❌
Word/Google Docs paste cleanup	❌
Selection preservation across toolbar	⚠️
RTL/bidirectional text	❌
Mobile virtual-keyboard behavior	❌

P2 — Common productivity

Feature	Status
Image URL + alt/title/removal	❌
Text color/highlight	❌
Text alignment	❌
Toolbar undo/redo	❌
Search and replace	❌
Automatic URL linking	❌
Subscript/superscript	❌
List indentation (Tab / Shift+Tab)	❌
Color reset	❌
Code language selector	❌
Word/character count + limits	❌
Fullscreen editor	❌
Autosave status	❌
Print-friendly mode	❌
Markdown paste	❌
Mobile toolbar overflow	❌

P3 — Advanced media and interaction

Feature	Status
Image file picker, drag/drop, paste	❌
Upload progress/placeholder	❌
Image resize handles/captions	🚫/❌
Link bubble menu	🚫
Floating toolbar	❌
Slash commands	❌
Responsive bottom-sheet toolbar	❌

P4 — Document-model / v2

Feature	Status
Task lists	🚫
GFM tables	🚫
Markdown output mode	🚫
JSON output	🚫
Collaboration	🚫
Live syntax highlighting in editable code	🚫
Full image node view	🚫

Implementation order

1. Validate current editor with Playwright.
2. Harden sanitizer and intercept paste.
3. Split inline Code and CodeBlock.
4. Add paragraph + H1–H6 dropdown.
5. Add links.
6. Add blockquote, HR, hard break, and list keyboard rules.
7. Stabilize editor API: events, controlled value, reset, read-only.
8. Add image URL, color/highlight, alignment.
9. Add mobile overflow, search/replace, productivity features.
10. Re-evaluate architecture before advanced media/document-model features.

References: __TMP/shadcn-minimal-tiptap primary; __TMP/tiptap-shadcn secondary.