fix(custom-model): merge-time fixes for the promoted-model picker (#459)

The maintainer's promised follow-ups to opticon454's picker promotion,
applied on the landing branch after the merge (ecb95b5d):

- session-ui.js: the promotion tag ("Currently loaded" / "Last used") and
  the "Default" pill are two separate spans, so a promoted row that is
  also the endpoint's defaultModelId shows both instead of silently
  losing its Default marking; two tests pin it (both fail on the old
  exclusive-slot rendering).
- styles.css: a dedicated #customModelPickModal .set-scope rule, since
  the pill was only styled inside the three settings modals and rendered
  as plain body text here; same skin tokens, modal layout untouched.
- docs/wiki/Custom-Model-Endpoints.md: describe the promotion (currently
  loaded, else last used per device), the separate Default pill, and
  that nothing is ever auto-chosen.
- CLAUDE.md + docs/custom-model-endpoints.md: credit the real "Last used"
  writers (_runCustomModelEntryViaRestart and
  _quickStartWithCustomModelConfirm; runCustomModelEntry only dispatches
  since 88e5b7b2) and drop the now-wrong "both defer to Default" sentence.
- Not done: moving the one-shot "last used" write into
  _runCustomModelEntryOneShot, because the existing one-shot tests assert
  that _quickStartWithCustomModelConfirm writes the key itself.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
(cherry picked from commit 0cb0f911adc14a852ba5c2951768a4aa87c25657)

src/web/public/session-ui.js

@@ -825,12 +825,17 @@ Object.assign(CodemanApp.prototype, {
       `${cliLabel} → ${host.label} — ${(host.models || []).length} models discovered.`;
     list.innerHTML = models
       .map((m) => {
-        const isDefault = m === host.defaultModelId;
-        const tag = m === currentlyLoaded ? 'Currently loaded' : m === lastUsed ? 'Last used' : isDefault ? 'Default' : null;
+        // Two independent tags, never one exclusive slot: the promotion tag says what
+        // llama-swap (or this device's history) knows about the model, the Default pill
+        // says what the saved endpoint says about it, and on a single-purpose GPU box the
+        // promoted model IS the default more often than not. One slot holding whichever
+        // applied first silently dropped the Default marking for exactly that row.
+        const promotion = m === currentlyLoaded ? 'Currently loaded' : m === lastUsed ? 'Last used' : null;
+        const tags = [promotion, m === host.defaultModelId ? 'Default' : null].filter(Boolean);
         const arg = escapeHtml(JSON.stringify(m));
         return `
           <button class="run-mode-option" onclick="app.chooseCustomModelAndRun(${arg})">
-            <span class="run-mode-dot ${escapeHtml(mode)}"></span>${escapeHtml(m)}${tag ? ` <span class="set-scope">${escapeHtml(tag)}</span>` : ''}
+            <span class="run-mode-dot ${escapeHtml(mode)}"></span>${escapeHtml(m)}${tags.map((t) => ` <span class="set-scope">${escapeHtml(t)}</span>`).join('')}
           </button>`;
       })
       .join('');