docs: close Sprint 5/5.5, prepare Sprint 6

- fix: CeoBlock padding 40px 48px → 40px 0 (v1.2)
- fix: BlockMetaBar.saveFullVersion() used defaultVersion instead of meta.version, causing version rollback in DB on snapshot save
- docs: mark Sprint 5 and 5.5 as completed in SPRINTS.md
- docs: update LLM_CONTEXT v4.5 — all 8 blocks documented, Sprint 6 current
- chore: Sidebar version → Sprint 6 · v0.6.0
- chore: add .vercel to .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/components/ui/BlockMetaBar.tsx

@@ -134,8 +134,9 @@ export function BlockMetaBar({ path, defaultVersion, defaultIsInPreview, default
     if (apiDown || !apiUrl) return;
     setSavingVersion('saving');
     try {
-      // 1. Update block metadata
-      const updated = await patch({ version: defaultVersion, changelog: defaultChangelog });
+      // 1. Update block metadata (prefer current API version over hardcoded default)
+      const currentVersion = meta?.version ?? defaultVersion;
+      const updated = await patch({ version: currentVersion, changelog: defaultChangelog });
       if (updated) {
         setMeta(updated);
         setVersionInput(updated.version);
@@ -147,7 +148,7 @@ export function BlockMetaBar({ path, defaultVersion, defaultIsInPreview, default
         await fetch(`${apiUrl}/blocks/snapshots?path=${encodeURIComponent(path)}`, {
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({ version: defaultVersion, changelog: defaultChangelog, html, css }),
+          body: JSON.stringify({ version: currentVersion, changelog: defaultChangelog, html, css }),
         });
         await fetchSnapshots();
       } catch { /* snapshot capture may fail if container not found */ }