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/blocks/CeoBlock.tsx

@@ -15,7 +15,7 @@ export function CeoBlock() {
         fontSize: 14,
         lineHeight: 1.75,
         color: "#374151",
-        padding: "40px 48px",
+        padding: "40px 0",
       }}
     >
       <p>