SDK sandbox provisioning: built-in providers, docs restructure, and quickstart overhaul

- Add built-in sandbox providers (local, docker, e2b, daytona, vercel, cloudflare) to the TypeScript SDK so users import directly instead of passing client instances
- Restructure docs: rename architecture to orchestration-architecture, add new architecture page for server overview, improve getting started flow
- Rewrite quickstart to be TypeScript-first with provider CodeGroup and custom provider accordion
- Update all examples to use new provider APIs
- Update persist drivers and foundry for new SDK surface

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

docs/deploy/local.mdx

@@ -32,12 +32,15 @@ Or with npm/Bun:
 
 ## With the TypeScript SDK
 
-The SDK can spawn and manage the server as a subprocess:
+The SDK can spawn and manage the server as a subprocess using the `local` provider:
 
 ```typescript
 import { SandboxAgent } from "sandbox-agent";
+import { local } from "sandbox-agent/local";
 
-const sdk = await SandboxAgent.start();
+const sdk = await SandboxAgent.start({
+  sandbox: local(),
+});
 
 const session = await sdk.createSession({
   agent: "claude",
@@ -47,7 +50,21 @@ await session.prompt([
   { type: "text", text: "Summarize this repository." },
 ]);
 
-await sdk.dispose();
+await sdk.destroySandbox();
 ```
 
 This starts the server on an available local port and connects automatically.
+
+Pass options to customize the local provider:
+
+```typescript
+const sdk = await SandboxAgent.start({
+  sandbox: local({
+    port: 3000,
+    log: "inherit",
+    env: {
+      ANTHROPIC_API_KEY: process.env.MY_ANTHROPIC_KEY,
+    },
+  }),
+});
+```