docs(ui): the raw-button rule is 'outside the control primitives', and the README table is whole

CLAUDE.md, DESIGN.md and ui/README said a raw <button> is allowed anywhere in components/ui/; the
lint rule allows it only in BUTTON_PRIMITIVES (and refuses a bare FocusSafeButton elsewhere too).
The focus-safe rule's message no longer points feature code at FocusSafeButton. The README's
'actions & inputs' row was split in two by a stray line break.

frontend/eslint.config.js

@@ -69,7 +69,7 @@ const focusSafeDisabled = {
   meta: {
     type: "problem",
     messages: {
-      raw: "A raw <button disabled> throws a focused user to <body> when it turns disabled. Use ui/FocusSafeButton (or ui/Button).",
+      raw: "A raw <button disabled> throws a focused user to <body> when it turns disabled. Build the primitive on ui/FocusSafeButton; anywhere else use ui/Button, IconButton or Pressable.",
     },
   },
   create(context) {