[WIP] Add institution connectors and knowledge graph features

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>feat: institution connectors + knowledge graph + multi-agent MCP</issue_title>
<issue_description>## 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</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes feat: institution connectors + knowledge graph + multi-agent MCP #76

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[kayodebristol]

Closing this PR to enforce the 1-PR-per-repo rule. Only one Copilot PR is allowed per repository at a time. The oldest PR (#48) will be kept active.