fix(web): address PR review (clean .md output, one MCP config source)

- .md output rewrites MDX-only syntax (Tabs, TabItem, asides, the MCP
  client component) into plain Markdown.
- MCP client setups live in one data file used by the landing page, the
  setup page and agents/install; the smoke-test claim names the five
  agents agent-smoke.sh actually drives (not Cursor).
- The landing page reads the version from Cargo.toml; the hand-copied BBCA
  data stays dated, and the design doc no longer promises capture.sh.
- MCP overview counts 11 tools plus the opt-in ownership_sync.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/components/McpClientTabs.astro

@@ -0,0 +1,15 @@
+---
+import { Code, TabItem, Tabs } from '@astrojs/starlight/components';
+import { mcpClients } from '../data/mcp-clients';
+---
+
+<Tabs syncKey="agent">
+	{
+		mcpClients.map((c) => (
+			<TabItem label={c.label}>
+				<p>{/[~/]/.test(c.file) ? <code>{c.file}</code> : c.file}</p>
+				<Code code={c.code} lang={c.lang} />
+			</TabItem>
+		))
+	}
+</Tabs>