fix(ui): hold info toast ~1s before it rises and fades

The info toast began drifting up and fading the instant it finished
appearing (the CSS keyframes went straight from the 12% appeared-stop to
the 100% risen-and-faded stop), so a glanced message was already leaving.

Insert a ~1s hold at full opacity/rest before the rise-and-fade: extend the
animation 2s → 3s with keyframe stops at 8% (appeared, ~240ms) and 41% (end
of the ~1s hold), keeping the original rise-and-fade pace for the tail. The
reduced-motion variant gets the same appear/hold/fade timing (fade only, no
travel). The showToast dismissal timer is bumped 2000 → 3000ms to stay in
lockstep with the animation (the error toast's 4s dwell is unchanged).

ui/src/components/Toast.svelte

@@ -3,8 +3,9 @@
   import { app, dismissToast } from '../lib/app.svelte';
 
   const dur = $derived(app.reduceMotion ? 0 : 260);
-  // An info bubble owns its whole 2s life through a CSS rise-and-fade animation, so it takes
+  // An info bubble owns its whole 3s life through a CSS animation — appear, a ~1s hold at rest,
-  // no Svelte enter/leave transition; an error keeps the fly-in / fade-out dwell behaviour.
+  // then rise-and-fade — so it takes no Svelte enter/leave transition; an error keeps the fly-in /
+  // fade-out dwell behaviour.
   const isInfo = $derived(app.toast?.kind !== 'error');
 </script>
 
@@ -50,17 +51,19 @@
     border-color: var(--danger);
     color: var(--danger);
   }
-  /* An info bubble fades in, then drifts up by roughly the tab-bar height while fading out,
+  /* An info bubble fades in, holds for ~1s at rest, then drifts up by roughly the tab-bar height
-     all within 2s; the X centring is preserved across the rise. */
+     while fading out, all within 3s; the X centring is preserved across the rise. The 8%/41%
+     stops are the appear (~240ms) and the end of the ~1s hold. */
   .toast.rise {
-    animation: toast-rise 2s ease-out forwards;
+    animation: toast-rise 3s ease-out forwards;
   }
   @keyframes toast-rise {
     0% {
       opacity: 0;
       transform: translateX(-50%) translateY(8px);
     }
-    12% {
+    8%,
+    41% {
       opacity: 1;
       transform: translateX(-50%) translateY(0);
     }
@@ -69,16 +72,16 @@
       transform: translateX(-50%) translateY(-56px);
     }
   }
-  /* Reduced motion: the same 2s life, fade only — no upward travel. */
+  /* Reduced motion: the same 3s life (appear, ~1s hold, fade), fade only — no upward travel. */
   .toast.rise-reduced {
-    animation: toast-rise-reduced 2s ease-out forwards;
+    animation: toast-rise-reduced 3s ease-out forwards;
   }
   @keyframes toast-rise-reduced {
     0% {
       opacity: 0;
     }
-    12%,
+    8%,
-    70% {
+    41% {
       opacity: 1;
     }
     100% {

ui/src/lib/app.svelte.ts

@@ -214,9 +214,9 @@ function goForeground(): void {
 export function showToast(text: string, kind: Toast['kind'] = 'info'): void {
   app.toast = { kind, text, seq: ++toastSeq };
   if (toastTimer) clearTimeout(toastTimer);
-  // An info bubble lives exactly as long as its rise-and-fade animation (2s); an error
+  // An info bubble lives exactly as long as its appear + ~1s hold + rise-and-fade animation (3s);
-  // dwells longer (4s) so it is not missed.
+  // an error dwells longer (4s) so it is not missed.
-  toastTimer = setTimeout(() => (app.toast = null), kind === 'error' ? 4000 : 2000);
+  toastTimer = setTimeout(() => (app.toast = null), kind === 'error' ? 4000 : 3000);
 }
 
 /** dismissToast hides the current toast at once — a tap on the bubble dismisses it. */