feat(wallet): tuck manual URI under an "Advanced" disclosure (Bitcoin Connect D5)

When FEATURE_BITCOIN_CONNECT is on, "Connect wallet" is the primary path and the
raw Wallet Connect URI field collapses under an "Advanced — paste a connection
manually" <details> disclosure (backup, de-emphasized). When the flag is off, the
controller forces the disclosure open and hides its summary, so the URI field
shows plainly exactly as before (no behavior change). Default-zap field stays
always visible. Adds a small token-based rotating-caret style for the summary.

Still LOCAL (flag ON for testing); not pushed, not deployed.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

css/tailwind.source.css

@@ -580,6 +580,25 @@
     display: none;
   }
 
+  /* "Advanced — paste a connection manually" disclosure in the Wallet pane
+     (Bitcoin Connect). A subtle rotating caret replaces the default marker. */
+  .wallet-advanced__summary {
+    list-style: none;
+  }
+
+  .wallet-advanced__summary::-webkit-details-marker {
+    display: none;
+  }
+
+  .wallet-advanced__summary::before {
+    content: "▸ ";
+    color: var(--text-subtle);
+  }
+
+  .wallet-advanced[open] > .wallet-advanced__summary::before {
+    content: "▾ ";
+  }
+
   .popularity-modal__backdrop {
     z-index: var(--z-overlay-popover);
     padding: var(--space-md);