Append-only shared context store for Converge.

This service is derivative, not authoritative:

• It remembers what already happened
• It never decides or coordinates convergence
• It may lose data (the Rust engine can regenerate)
• It never mutates or rewrites history

The Rust engine remains the single semantic authority.

API

The minimal API is exposed via gRPC:

• Append(context_id, key, payload) - Add an entry
• Get(context_id) - Retrieve all entries
• Snapshot(context_id) - Create a portable snapshot
• Load(context_id, blob) - Restore from a snapshot
• Watch(context_id) - Stream new entries (optional)

Non-Goals

This service explicitly does NOT support:

• Conditional updates
• Transactions across contexts
• Locks
• Conflict resolution
• Branching
• Deletes

If you need any of these, the design is wrong.

Usage

The service starts automatically when the application starts. Connect via gRPC on port 50051 (or GRPC_PORT env var).

# Local Elixir API (for testing)
{:ok, entry} = ConvergeLedger.append("my-context", "facts", payload)
{:ok, entries, seq} = ConvergeLedger.get("my-context")
{:ok, blob, seq, meta} = ConvergeLedger.snapshot("my-context")
{:ok, count, seq} = ConvergeLedger.load("my-context", blob)