feat: institution connectors + knowledge graph + multi-agent MCP

[kayodebristol]

Summary

Phase 4 — long-term platform capabilities.

Institution Connectors

• Connect to bank/credit card APIs for automatic import
• Replace file-based ingestion for supported institutions
• Maintain manual import as fallback

Knowledge Graph

• Full knowledge-graph representation of financial entities
• Merchants, categories, accounts, transactions as graph nodes
• Relationships: "pays for", "transfers to", "recurring from", "categorized as"
• Use PluresDB graph capabilities

Multi-Agent MCP

• Expose stable domain operations via MCP server
• Enable multi-agent analysis (praxis procedures calling MCP tools)
• Cross-project integration with pares-agens, PluresDB, chronos, unum

Integration Principles

• Use plures org projects first before external dependencies
• If an external tool could be better built with praxis, build it ourselves
• PluresDB for storage, chronos for scheduling, unum for identity

Acceptance

• At least one institution connector working
• Knowledge graph queryable
• MCP server exposes real domain operations
• Cross-project integration demonstrated