feat: add Brain Protocol MCP — persistent memory for Snak agents

[seritalien]

Summary

Add Brain Protocol as an MCP server integration, providing persistent, searchable, graph-connected memory for Snak AI agents.

• 23 tools including knowledge CRUD, graph traversal, export/import, Starknet proof anchoring, agent intelligence (pattern suggestion, anti-pattern detection, architectural advice), Giza zkML proofs, and usage metering
• Zero config: `npx @brain-protocol/mcp` — starts with local SQLite, no setup needed
• Cloud mode: optional sync to Brain Protocol API with on-chain verification via Starknet, with built-in retry + circuit breaker
• Decision intelligence: suggest patterns, detect anti-patterns, and get architectural advice based on accumulated knowledge

Tools (23)

Category	Tools
Knowledge CRUD	`archive_knowledge`, `query_knowledge`, `update_knowledge`, `delete_knowledge`
Graph	`create_edge`, `traverse_graph`, `get_graph_overview`
Data	`export_knowledge`, `import_knowledge`
Starknet	`anchor_to_l3`, `prove_knowledge`
Agents	`get_agent_stats`, `log_agent_task`
Decision Intelligence	`suggest_patterns`, `detect_antipatterns`, `architectural_advice`
Giza zkML	`archive_giza_proof`, `query_giza_proofs`, `link_proof_to_entry`
Metering	`get_usage`
System	`get_brain_status`, `list_categories`, `get_entry_detail`

Files added

File	Purpose
`examples/brain_mcp.json`	Local mode config (zero dependencies)
`examples/brain_cloud_mcp.json`	Cloud mode with API key
`examples/brain_example.ts`	Full example: archive, query, stats
`README.md`	Added Brain Protocol section to examples list

Why this matters

Brain Protocol closes the Trust Triangle for Starknet AI:

• Snak (Execution) — the agent acts
• Brain Protocol (Memory) — the agent remembers with cryptographic proof
• Giza (Verification) — the agent proves its inference

Links

• npm: @brain-protocol/mcp
• Repo: seritalien/brain-protocol
• Docs: examples/snak/

Test plan

• Verify `brain_mcp.json` is valid JSON
• Verify `brain_cloud_mcp.json` is valid JSON
• Run `npx @brain-protocol/mcp --check` confirms server starts
• Run `brain_example.ts` successfully connects and archives knowledge