More chat icons; message menu inside the bubble

- 18 more icons (gamepad, computer, food, ...) with a test that keeps the
  server whitelist and the client picker identical.
- The ⋯ menu of a message moves into the bubble foot (next to the time); its
  popup opens upwards inside the bubble and is limited to the bubble's width.

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

web/src/components/ColorSwatches.tsx

@@ -8,6 +8,7 @@ export const SESSION_COLORS = ["red", "orange", "yellow", "green", "aqua", "blue
 export const SESSION_ICONS = [
   "robot", "brain", "terminal", "wrench", "gear", "chart", "shield", "image", "music", "cube", "file-text", "folder", "search", "sparkle", "clock", "lock",
   "users", "toolbox", "plug", "scroll", "eye", "template",
+  "gamepad", "computer", "food", "coffee", "home", "book", "code", "camera", "cart", "heart", "star", "globe", "calendar", "car", "plane", "bulb", "money", "palette",
 ] as const;
 
 /** Row of colour dots; the selected one is ringed, a second click removes the tag. */