Add markdown support

[jhodapp]

Description

Enable full markdown interpretation in coaching notes editor, including markdown table paste support and enhanced link handling with keyboard shortcuts.

GitHub Issue: Closes #189

Changes

• Markdown Table Support: Added markdown table parsing and rendering with @tiptap/extension-table integration

  • Created markdown-table-extension.tsx with custom parse/render handlers for marked.js
  • Added TableMarkdownPasteHandler extension for clipboard paste detection
  • Configured table with resizable: false due to known Yjs collaboration conflict
  • Added table styling in tiptap-table.scss with borders, padding, and header backgrounds

• TipTap Extension Configuration Fixes:

  • Replaced StarterKit with individual extension imports to avoid History/Collaboration conflict
  • Added missing Underline extension (was referenced in toolbar but not configured)
  • Fixed TypeScript errors in link extension by explicitly defining attributes

• Link Keyboard Shortcut (CMD+K / Ctrl+K):

  • Added LinkKeyboardShortcut extension for CMD+K/Ctrl+K support
  • Created shared triggerLinkCreation() utility to eliminate duplication between button and keyboard
  • Centralized zombie link cleanup into LinkZombieCleanup extension for consistent behavior

• Code Quality:

  • Added comprehensive tests in coaching-notes-markdown-extensions.test.tsx (3 passing tests)
  • Tests cover markdown table conversion and autolink functionality
  • Removed duplicate cleanup logic from LinkBubbleMenu component

Screenshots / Videos Showing UI Changes (if applicable)

Markdown tables and links converted to rich text in light mode:

Markdown tables and links converted to rich text in dark mode:

Testing Strategy

Manual Testing:

1. Paste markdown table (e.g., from GitHub) into coaching notes - should render as formatted table
2. Highlight text → press CMD+K (Mac) or Ctrl+K (Windows) → bubble menu should appear
3. Create link via CMD+K but don't enter URL → click away → zombie link should be automatically removed
4. Verify underline button works in toolbar
5. Check no console warnings for duplicate extensions or History/Collaboration conflicts

Some valid and invalid markdown tables and links for manual testing

// Simple valid table:
| Name | Age |
| ---  | --- |
| Alice | 30 |


// Empty table:
|     |
| --- |


// Empty header row table:
|     |         | 
| --- | ---     |
| Cell1 | Cell2 |


// Simple valid table but with leading spaces:
  | Name | Age |
  | ---  | --- |
  | Alice | 30 |


// Simple valid table but with different leading spaces:
  | Name | Age |
      | ---  | --- |
| Alice | 30 |



// Malformed table that looks like a table:
| Name | Age |
| Alice | 30 |


// Invalid table with leading tabs:
      | Name | Age |
      | --- | ---  |
      | Bob | 25   |

// Valid Markdown link with spaces
   [Example Title](https://example.com)

Automated Testing:

npm test -- __tests__/components/ui/coaching-sessions/coaching-notes/coaching-notes-markdown-extensions.test.tsx
npm run typecheck

Concerns

• Extension Order: The LinkZombieCleanup extension must be loaded for proper empty link cleanup - ensure it's included in the extensions array.

[calebbourg]

Just the one suggestion on toast messages. Otherwise looks great!

[calebbourg]

Matching on actual error output strings is usually fairly brittle in my own experience. This one seems pretty specific as well since, I would assume, user's will be using more than just tables. I like the generic toast message below. That, to me, would handle all cases well.

[jhodapp]

Ah yes good catch. I had Claude break this out into a general error function, but it didn't rework the overly specific error here.

[jhodapp]

Addressed in 6fb18fc

[calebbourg]

Looks great!