feat: add paperclip-memory cookbook example

[benfrank241]

Summary

• Adds applications/paperclip-memory/ cookbook entry for Paperclip AI agents with Hindsight memory
• Two runnable TypeScript examples: Process adapter (process-agent.ts) and HTTP adapter (http-agent.ts)
• Uses hindsight-paperclip npm package

Examples

• process-agent.ts — direct recall() + retain() usage; run twice to see memory persist across heartbeats
• http-agent.ts — Express server with createMemoryMiddleware(); auto-recalls before each request and auto-retains agent output

Test plan

• npm install && npx ts-node --esm process-agent.ts — first run shows no memories, second run recalls prior output
• npx ts-node --esm http-agent.ts + curl — memories injected and auto-retained