```

chore: remove obsolete files and add Solidity build artifacts to .gitignore

- Add ignore patterns for Solidity build artifacts (typechain-types, artifacts, cache)
- Remove unused exchange mock API server (api/exchange_mock_api.py)
- Remove obsolete client-web README placeholder
- Remove deprecated marketplace-ui HTML implementation
```

docs/reference/components/blockchain_node.md

@@ -0,0 +1,55 @@
+# Blockchain Node – Task Breakdown
+
+## Status (2025-12-22)
+
+- **Stage 1**: ✅ **DEPLOYED** - Blockchain Node successfully deployed on host with RPC API accessible
+  - SQLModel-based blockchain with PoA consensus implemented
+  - RPC API running on port 9080 (proxied via /rpc/)
+  - Mock coordinator on port 8090 (proxied via /v1/)
+  - Devnet scripts and observability hooks implemented
+  - Note: SQLModel/SQLAlchemy compatibility issues remain (low priority)
+
+## Stage 1 (MVP) - COMPLETED
+
+- **Project Scaffolding**
+  - ✅ Create `apps/blockchain-node/src/` module layout (`types.py`, `state.py`, `blocks.py`, `mempool.py`, `consensus.py`, `rpc.py`, `p2p.py`, `receipts.py`, `settings.py`).
+  - ✅ Add `requirements.txt` with FastAPI, SQLModel, websockets, orjson, python-dotenv.
+  - ✅ Provide `.env.example` with `CHAIN_ID`, `DB_PATH`, bind addresses, proposer key.
+
+- **State & Persistence**
+  - ✅ Implement SQLModel tables for blocks, transactions, accounts, receipts, peers, params.
+  - ✅ Set up database initialization and genesis loading.
+  - ✅ Provide migration or reset script under `scripts/`.
+
+- **RPC Layer**
+  - ✅ Build FastAPI app exposing `/rpc/*` endpoints (sendTx, getTx, getBlock, getHead, getBalance, submitReceipt, metrics).
+  - ✅ Implement admin endpoints for devnet (`mintFaucet`, `paramSet`, `peers/add`).
+
+- **Consensus & Block Production**
+  - ✅ Implement PoA proposer loop producing blocks at fixed interval.
+  - ✅ Integrate mempool selection, receipt validation, and block broadcasting.
+  - ✅ Add basic P2P gossip (websocket) for blocks/txs.
+
+- **Receipts & Minting**
+  - ✅ Wire `receipts.py` to coordinator attestation mock.
+  - ✅ Mint tokens to miners based on compute_units with configurable ratios.
+
+- **Devnet Tooling**
+  - ✅ Provide `scripts/devnet_up.sh` launching bootstrap node and mocks.
+  - ✅ Document curl commands for faucet, transfer, receipt submission.
+
+## Production Deployment Details
+
+- **Host**: Running on host machine (GPU access required)
+- **Service**: systemd services for blockchain-node, blockchain-rpc, mock-coordinator
+- **Ports**: 9080 (RPC), 8090 (Mock Coordinator)
+- **Proxy**: nginx routes /rpc/ and /v1/ to host services
+- **Access**: https://aitbc.bubuit.net/rpc/ for blockchain RPC
+- **Database**: SQLite with SQLModel ORM
+- **Issues**: SQLModel/SQLAlchemy compatibility (low priority)
+
+## Stage 2+ - IN PROGRESS
+
+- 🔄 Upgrade consensus to compute-backed proof (CBP) with work score weighting.
+- 🔄 Introduce staking/slashing, replace SQLite with PostgreSQL, add snapshots/fast sync.
+- 🔄 Implement light client support and metrics dashboard.