Write text blocks with formatting

Tiptap replaces the plain textarea: bold, italic, subheading, lists and
links. Stored as Markdown so API clients keep reading and writing the
same field, rendered with react-markdown.

package.json

@@ -18,6 +18,11 @@
 		"publish:due": "tsx scripts/publish-due.ts"
 	},
 	"dependencies": {
+		"@tiptap/extension-link": "^3.29.2",
+		"@tiptap/extensions": "^3.29.2",
+		"@tiptap/pm": "^3.29.2",
+		"@tiptap/react": "^3.29.2",
+		"@tiptap/starter-kit": "^3.29.2",
 		"better-auth": "1.6.25",
 		"drizzle-orm": "0.45.2",
 		"next": "16.2.12",
@@ -29,7 +34,10 @@
 		"react": "19.2.8",
 		"react-dom": "19.2.8",
 		"react-icons": "5.7.0",
+		"react-markdown": "^10.1.0",
+		"remark-gfm": "^4.0.1",
 		"sharp": "^0.35.3",
+		"tiptap-markdown": "^0.9.0",
 		"zod": "4.4.3"
 	},
 	"devDependencies": {