feat(model-manager): flag Early Access models in CivitAI browse

CivitAI Early Access versions require purchased access and otherwise fail
with 401. Surface version `availability` from the API as an `early_access`
flag (per card and per version), show an amber "EARLY ACCESS" tag on the
card, label such entries in the version dropdown, and warn before
attempting to download one.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

model-manager/app/static/app.js

@@ -477,6 +477,12 @@ function renderBrowseCard(m) {
     n.textContent = "NSFW";
     thumb.appendChild(n);
   }
+  if (m.early_access) {
+    const ea = document.createElement("span");
+    ea.className = "ea-tag";
+    ea.textContent = "EARLY ACCESS";
+    thumb.appendChild(ea);
+  }
 
   const body = document.createElement("div");
   body.className = "body";
@@ -497,7 +503,8 @@ function renderBrowseCard(m) {
     for (const v of m.versions) {
       const o = document.createElement("option");
       o.value = v.id;
-      o.textContent = v.name || `v${v.id}`;
+      o.textContent = (v.name || `v${v.id}`) + (v.early_access ? " — Early Access" : "");
+      o.dataset.ea = v.early_access ? "1" : "";
       versionSel.appendChild(o);
     }
     foot.appendChild(versionSel);
@@ -507,8 +514,15 @@ function renderBrowseCard(m) {
   btn.className = "btn primary";
   btn.textContent = "Download";
   btn.addEventListener("click", () => {
-    const vid = versionSel ? Number(versionSel.value) : m.primary_version_id;
-    downloadVersion(vid, btn);
+    let vid, isEa;
+    if (versionSel) {
+      vid = Number(versionSel.value);
+      isEa = versionSel.selectedOptions[0]?.dataset.ea === "1";
+    } else {
+      vid = m.primary_version_id;
+      isEa = m.early_access;
+    }
+    downloadVersion(vid, btn, isEa);
   });
   foot.appendChild(btn);
 
@@ -517,8 +531,15 @@ function renderBrowseCard(m) {
   return card;
 }
 
-async function downloadVersion(versionId, btn) {
+async function downloadVersion(versionId, btn, isEarlyAccess) {
   if (!versionId) { toast($("#browseToast"), "No version available", true); return; }
+  if (isEarlyAccess) {
+    const ok = await confirmDialog(
+      "This is an Early Access version. CivitAI only allows downloading it if " +
+      "your account has purchased/unlocked access — otherwise it will fail with " +
+      "401. Try anyway?", "Download");
+    if (!ok) return;
+  }
   btn.disabled = true;
   const original = btn.textContent;
   btn.textContent = "Queued ✓";