feat(local-model): the start screen's local model button in the size of the main one

The owner asked for it much bigger and in the middle. The button keeps the
chip's markup and takes the primary button's height, radius and weight, with
an accent outline and its glyph in a disc, so a model on this Mac is offered
as a main way in rather than as a footnote under the launchers.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/web/public/styles.css

@@ -22327,9 +22327,31 @@ html[data-tile-anim="soft"] .tile-grid-ghosts.tile-grid-ghosts--release:not(.til
    body scrolling between them. A click never moves the next button away.
    ═══════════════════════════════════════════════════════════════ */
 
-/* The welcome button: one more chip, on its own line under the launchers. */
+/* The welcome button: a second large button under the launchers, in the size
+   of the primary one, so a model on this Mac is offered as a main way in and
+   not as a footnote (the owner asked for it big and in the middle). It keeps
+   the chip's markup and the chip family's rules for everything it does not
+   restate here. */
 .welcome-local-model {
   margin-top: 1.1rem;
+  height: 46px;
+  gap: 0.65rem;
+  padding: 0 1.4rem 0 0.45rem;
+  border: 1px solid var(--accent);
+  border-radius: 23px;
+  background: var(--control-bg);
+  color: var(--accent);
+  font-size: 0.95rem;
+  font-weight: 700;
+  letter-spacing: 0.005em;
+  box-shadow: 0 8px 24px -14px rgba(var(--accent-rgb), 0.5);
+}
+
+.welcome-local-model:hover,
+.welcome-local-model:focus-visible {
+  background: rgba(var(--accent-rgb), 0.12);
+  color: var(--accent);
+  border-color: var(--accent);
 }
 
 /* `.welcome-chip` is inline-flex, so `[hidden]` needs re-asserting or the
@@ -22338,8 +22360,15 @@ html[data-tile-anim="soft"] .tile-grid-ghosts.tile-grid-ghosts--release:not(.til
   display: none;
 }
 
+/* The chip's 14 px glyph sits in a 34 px disc, the primary button's logo size. */
 .welcome-local-model svg {
   flex-shrink: 0;
+  width: 34px;
+  height: 34px;
+  padding: 8px;
+  box-sizing: border-box;
+  border-radius: 50%;
+  background: rgba(var(--accent-rgb), 0.16);
 }
 
 /* The window: App Settings' chrome (`.modal`, `.modal-header`, the boxed