fix: migrate geo shapes with props.text during Automerge load

Geo shapes saved before the tldraw schema change have props.text which is
no longer valid. This causes ValidationError on page reload when shapes are
loaded from Automerge:

  "ValidationError: At shape(type = geo).props.text: Unexpected property"

The migration logic was only in JSON import (CustomMainMenu.tsx), but shapes
loading from Automerge also need migration.

This fix adds the props.text → props.richText migration to the sanitizeRecord
function in AutomergeToTLStore.ts, ensuring geo shapes are properly migrated
when loaded from Automerge, matching the behavior during JSON import.

The original text is preserved in meta.text for backward compatibility with
search and other features that reference it.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/automerge/AutomergeToTLStore.ts

@@ -769,6 +769,33 @@ export function sanitizeRecord(record: any): TLRecord {
       }
     }
     
+    // CRITICAL: Convert props.text to props.richText for geo shapes (tldraw schema change)
+    // tldraw no longer accepts props.text on geo shapes - must use richText
+    // This migration handles shapes that were saved before the schema change
+    if (sanitized.type === 'geo' && 'text' in sanitized.props && typeof sanitized.props.text === 'string') {
+      const textContent = sanitized.props.text
+
+      // Convert text string to richText format for tldraw
+      sanitized.props.richText = {
+        type: 'doc',
+        content: textContent ? [{
+          type: 'paragraph',
+          content: [{
+            type: 'text',
+            text: textContent
+          }]
+        }] : []
+      }
+
+      // CRITICAL: Preserve original text in meta.text for backward compatibility
+      // This is used by search (src/utils/searchUtils.ts) and other legacy code
+      if (!sanitized.meta) sanitized.meta = {}
+      sanitized.meta.text = textContent
+
+      // Remove invalid props.text
+      delete sanitized.props.text
+    }
+
     // CRITICAL: Fix richText structure for geo shapes (preserve content)
     if (sanitized.type === 'geo' && sanitized.props.richText) {
       if (Array.isArray(sanitized.props.richText)) {