merge origin/staging into the report translation fix (issue #53)

Docs-only conflict in BUG_HISTORY: BUG-1311 (#52) and BUG-1312..1315 (#53)
both appended after BUG-1310; kept both in number order. Product owner
chose option A on #53: Claude merges a stale branch when only docs conflict.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LutgzyJqNhPpZy1nFsJtN3

frontend/tests/chat-reading-load-mobile.test.ts

@@ -62,6 +62,10 @@ test("otp and composer keep their existing safe sizes", () => {
   assert.match(ruleFor(".composer textarea {"), /font-size:\s*var\(--type-body-md\)/);
 });
 
+test("composer textarea radius is 0 because a 0 left padding clips the first glyph on rounded corners", () => {
+  assert.match(ruleFor(".composer textarea {"), /border-radius:\s*0/);
+});
+
 test("personal-report tables are not retargeted by the chat wide-table rule", () => {
   const mobile = css.slice(css.indexOf("@media (max-width: 767px)"));
   const wide = mobile.match(