feat(web): write descriptions and comments with a visual editor

ts-rich-editor (TipTap) shows the formatting while writing: bold,
italic, strike, code, headings, lists, task lists, quotes, code blocks
and links, with @ suggesting the project's members and pasted
screenshots uploaded as attachments. It reads and writes the same
Markdown the API keeps (mentions as @[Name](id), images as
attachment:<id>, tables too), so nothing already written changes.

Used for comments, replies, editing a comment or a description, a new
ticket from the board and the public proposal form; the Markdown hint
and the paste directive are gone. List markers sat on a line of their
own, and task lists showed a stray bullet, in the editor and when read.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package.json

@@ -35,6 +35,16 @@
     "@ngx-translate/core": "^18.0.0",
     "@ngx-translate/http-loader": "^18.0.0",
     "@pi/ui": "^0.0.5",
+    "@tiptap/core": "3.31.3",
+    "@tiptap/extension-image": "3.31.3",
+    "@tiptap/extension-list": "3.31.3",
+    "@tiptap/extension-mention": "3.31.3",
+    "@tiptap/extension-table": "3.31.3",
+    "@tiptap/extensions": "3.31.3",
+    "@tiptap/markdown": "3.31.3",
+    "@tiptap/pm": "3.31.3",
+    "@tiptap/starter-kit": "3.31.3",
+    "@tiptap/suggestion": "3.31.3",
     "apollo-angular": "^14.2.0",
     "chart.js": "^4.5.1",
     "class-transformer": "^0.5.1",