Site polish, SDK rename, documentation overhaul

- OG meta URL fix, Dockerfile arch detection
- Core: validation from ColumnDef on mount, print to body, change tracking lifecycle
- Plugin showcase WitTable style prop, filter button CSS alignment
- Extract shared DemoButton (default/primary/toggle) and DemoToolbar components across 9 demos
- Cache-control headers: no-cache for HTML, immutable for hashed assets
- Replace 12 ASCII diagrams with Mermaid SVGs across 9 doc pages
- Rename all Wit* prefixes to Spreadsheet* in public SDK (18 identifiers, 170 files)
- Pre-release SDK audit: 171 findings catalogued
- Remove 13 deprecated Wit* aliases, eliminate 14 as-any casts via EventBus string overloads
- Document 83 previously undocumented exports (5 .mdx files, 1040 lines)
- Add 'Made with Moira' branding footer on all site pages
- Remove CLAUDE.md from git tracking

Author: witqq

.gitignore

@@ -23,3 +23,4 @@ moira-ws/
 .supervisor_logs/
 .idea/
 docker-compose.remote.yml
+CLAUDE.md

CLAUDE.md

@@ -10,7 +10,13 @@ COPY packages/server/package.json packages/server/
 COPY packages/demo/package.json packages/demo/
 COPY packages/site/package.json packages/site/
 RUN --mount=type=cache,target=/root/.npm \
-    npm ci && npm install @rollup/rollup-linux-x64-gnu @pagefind/linux-x64 --no-save
+    npm ci && \
+    ARCH=$(uname -m) && \
+    if [ "$ARCH" = "x86_64" ]; then \
+      npm install @rollup/rollup-linux-x64-gnu @pagefind/linux-x64 --no-save; \
+    elif [ "$ARCH" = "aarch64" ]; then \
+      npm install @rollup/rollup-linux-arm64-gnu @pagefind/linux-arm64 --no-save; \
+    fi
 
 FROM deps AS build
 COPY packages/core/ packages/core/

config/Dockerfile

@@ -9,19 +9,27 @@ server {
 
     # Demo SPA at /demo/
     location /demo/visual-tests {
+        add_header Cache-Control "no-cache";
         try_files $uri $uri/ /demo/visual-tests.html;
     }
 
     location /demo/ {
+        add_header Cache-Control "no-cache";
         try_files $uri $uri/ /demo/index.html;
     }
 
     # Site (landing + docs) at /
     location / {
+        add_header Cache-Control "no-cache";
         try_files $uri $uri/index.html $uri/ =404;
     }
 
-    # Static assets: long cache
+    # HTML: always revalidate (ETag + Last-Modified served by nginx automatically)
+    location ~* \.html$ {
+        add_header Cache-Control "no-cache";
+    }
+
+    # Hashed assets (Vite/Astro add content hash to filenames): long cache
     location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff2?)$ {
         expires 1y;
         add_header Cache-Control "public, immutable";