Linked Designs: Credits — display names + working profile links

Two fixes to the Credits panel + preview surface:

1. Anchor click routed through openProfilePage(pk) instead of
   navigating to /u/<npub> — the latter 404s because the SPA only
   handles those routes via JS, there's no static file behind them.
   Mirrors the pattern used by the existing author link in the
   preview header (preventDefault + openProfilePage).

2. Display name pulled from _feedCache.profiles / state.community
   .profiles with shortPubkey() as fallback. For contributors who
   aren't in the cache yet, _hydrateCreditProfiles fetches kind-0
   metadata via populateCommunityProfiles in the background and
   re-renders the list when names arrive. Per-pubkey inflight
   tracking dedupes concurrent fetches across re-renders.

Editor panel re-renders the full panel on hydration. Preview
section rebuilds just its <ul> in place, guarded on
section.isConnected so a closed or swapped-out preview doesn't
mutate stale DOM.

src/index.html

@@ -6719,8 +6719,11 @@
 
     // Build a <ul> of contributor entries from a credits entry array.
     // Returns null when there are no contributors so callers can skip
-    // rendering an empty container. Each entry is an anchor to the
-    // /u/<npub> profile page with a short npub label.
+    // rendering an empty container. Each entry is an anchor that
+    // routes through openProfilePage so the SPA handles navigation
+    // (a bare `/u/<npub>` href 404s — there's no static file).
+    // Display name comes from the profile cache when available;
+    // falls back to a short pubkey so the row never reads as empty.
     function buildCreditsListElement(entries) {
       if (!entries.length) return null;
       const ul = document.createElement('ul');
@@ -6728,15 +6731,19 @@
       for (const [pk, refs] of entries) {
         const li = document.createElement('li');
         li.style.cssText = 'margin:4px 0;line-height:1.35';
-        const a = document.createElement('a');
-        a.href = profileUrlForPubkey(pk);
-        a.target = '_blank';
-        a.rel = 'noopener noreferrer';
-        a.style.cssText = 'font-family:monospace;color:#1e40af;text-decoration:none';
+        const profile = _feedCache.profiles?.[pk] || state.community?.profiles?.[pk] || null;
+        const name = profile?.display_name || profile?.name || shortPubkey(pk);
         let np = '';
         try { np = encodeNpub(pk); } catch {}
-        a.textContent = '@' + (np ? np.slice(0, 12) + '…' + np.slice(-6) : pk.slice(0, 10) + '…');
+        const a = document.createElement('a');
+        a.href = profileUrlForPubkey(pk);
+        a.textContent = '@' + name;
         a.title = np || pk;
+        a.style.cssText = 'color:#1e40af;text-decoration:none;cursor:pointer';
+        a.addEventListener('click', (e) => {
+          e.preventDefault();
+          openProfilePage(pk);
+        });
         li.appendChild(a);
         const count = document.createElement('span');
         count.style.cssText = 'color:#666;margin-left:4px';
@@ -6747,6 +6754,35 @@
       return ul;
     }
 
+    // Profile-metadata hydration for the Credits panel. The
+    // collectLinkedCredits walker only knows pubkeys (parsed from
+    // the address coord) — display names come from kind-0 events
+    // that aren't always cached. Fetch any uncached contributors
+    // in the background, then call onUpdate so callers can rebuild
+    // their UI with the freshly-resolved names. Per-pubkey inflight
+    // tracking prevents duplicate relay round-trips when render()
+    // fires repeatedly during the same fetch.
+    const _creditsProfileInflight = new Set();
+    async function _hydrateCreditProfiles(entries, onUpdate) {
+      if (!entries.length) return;
+      const uncached = entries
+        .map(([pk]) => pk)
+        .filter((pk) =>
+          !_creditsProfileInflight.has(pk) &&
+          !(_feedCache.profiles?.[pk] || state.community?.profiles?.[pk])
+        );
+      if (!uncached.length) return;
+      for (const pk of uncached) _creditsProfileInflight.add(pk);
+      try {
+        await populateCommunityProfiles(uncached);
+      } catch (err) {
+        console.warn('[credits] profile fetch failed', err);
+      } finally {
+        for (const pk of uncached) _creditsProfileInflight.delete(pk);
+      }
+      if (typeof onUpdate === 'function') onUpdate();
+    }
+
     // Editor-mode Credits panel (LINKED_DESIGNS_FEATURE.md §10.1).
     // Lives in the metadata sidebar; hidden when there are no
     // linked layers so non-collaborative designs stay clutter-free.
@@ -6765,6 +6801,10 @@
       // pre-applied styles on the fieldset stay coherent.
       while (ul.firstChild) list.appendChild(ul.firstChild);
       fieldset.style.display = '';
+      // Kick off profile fetches for any contributors we don't have
+      // names for yet; on completion, re-render so the @short-pubkey
+      // labels upgrade to display names.
+      _hydrateCreditProfiles(entries, renderCreditsPanel);
     }
 
     // Pre-publish hook. Linked layers carry render-only fields
@@ -23329,13 +23369,26 @@
         h.style.cssText = 'font-weight:600;font-size:.85rem;margin-bottom:4px';
         h.textContent = '🔗 Credits';
         wrap.appendChild(h);
-        wrap.appendChild(buildCreditsListElement(credits));
+        let ul = buildCreditsListElement(credits);
+        wrap.appendChild(ul);
         const note = document.createElement('p');
         note.className = 'hint';
         note.style.cssText = 'margin:6px 0 0;font-size:.7rem';
         note.textContent = 'Contributors reachable via linked layers in this design.';
         wrap.appendChild(note);
         content.appendChild(wrap);
+        // Same hydration dance as the editor panel — but here the
+        // re-render rebuilds just this <ul> in place. Guarded on
+        // section.isConnected so a closed/swapped preview doesn't
+        // mutate stale DOM.
+        _hydrateCreditProfiles(credits, () => {
+          if (!wrap.isConnected) return;
+          const fresh = buildCreditsListElement(credits);
+          if (fresh && ul.parentNode === wrap) {
+            wrap.replaceChild(fresh, ul);
+            ul = fresh;
+          }
+        });
       }
     }