Document Architecture and Extract DIFP Protocol

[Moses-Code-Dev]

This submission documents the architecture of the Djowda DIFP Android Playground and extracts the formal DIFP protocol specification.

• ARCHITECTURE.md: Explains the modular Gradle structure, the "Interactor" pattern for component coordination, and the "Four-Node Pattern" used for atomic writes in the Firebase reference implementation.
• DIFP_PROTOCOL.md: Distills the core coordination protocol into a language-agnostic specification. It includes the MinMax99 spatial grid algorithm, Decentralized Identifier (DID) format, schemas for presence and trades, and the formal message envelope for protocol federation.

These documents are designed to enable developers to understand the current implementation and build interoperable food ecosystem components on any platform.

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PR created automatically by Jules for task 10565993110785247549 started by @Moses-Code-Dev

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