Settings: clamp logo SVGs to 18px chip + endpoint dropdown gets logo

Provider SVGs in providers.js declare only viewBox (no width/height),
so when injected into the 18×18 logo chips they fell back to the
browser default of 300×150 and blew out the row.

- CSS: SVGs inside settings logo chips (`span[id$="-logo"]`,
  the 18px wrappers in fallback rows) now stretch to 100%/100% of
  their container.
- Added matching `-logo` chip next to the Endpoint dropdowns in
  Default Chat Model and Utility Model cards.
- New `_syncEndpointLogo` helper mirrors the selected endpoint
  option's text label through providerLogo() (the select value is
  a UUID and wouldn't match anything otherwise), and
  `_fillEndpointSelect` calls it on each render.

static/js/settings.js

@@ -239,6 +239,7 @@ function _fillEndpointSelect(selectEl, endpoints, selected, keepBlank) {
   } else if (blankText !== null) {
     selectEl.value = '';
   }
+  _syncEndpointLogo(selectEl);
 }
 
 // Mirror the selected model's provider logo into a sibling <span id="<selectId>-logo">.
@@ -256,6 +257,25 @@ function _syncModelLogo(selectEl) {
   }
 }
 
+// Same idea but for endpoint dropdowns where the <option value="…">
+// is an opaque endpoint UUID — fall back to the option's text label
+// so providerLogo() can pattern-match (Anthropic, OpenAI, Ollama, …).
+function _syncEndpointLogo(selectEl) {
+  if (!selectEl) return;
+  const logoEl = document.getElementById(selectEl.id + '-logo');
+  if (!logoEl) return;
+  const apply = () => {
+    const opt = selectEl.options[selectEl.selectedIndex];
+    const label = (opt && opt.textContent) || selectEl.value || '';
+    logoEl.innerHTML = providerLogo(label) || '';
+  };
+  apply();
+  if (!selectEl.dataset.epLogoSync) {
+    selectEl.dataset.epLogoSync = '1';
+    selectEl.addEventListener('change', apply);
+  }
+}
+
 function _fillModelSelect(selectEl, models, selected, keepBlank) {
   if (!selectEl) return;
   const previous = selected !== undefined ? selected : selectEl.value;