chore: initialize monorepo with project scaffolding, configs, and CI setup

protocols/receipts/samples/sample_receipt_signed.json

@@ -0,0 +1,28 @@
+{
+  "private_key_hex": "e2c35a46318ec09cf1cc04f06c4ba18bf2cd3f0ed318d986f01228bdbf9fd326",
+  "verify_key_hex": "4c9bc7d00f69924d1cdee40c3650a2bcbb37191de2d53d93b5f21b2d3d27dbd4",
+  "payload": {
+    "version": "1.0",
+    "receipt_id": "rcpt-20250926-000123",
+    "job_id": "job-abc123",
+    "provider": "ait1minerxyz...",
+    "client": "ait1clientabc...",
+    "units": 1.9,
+    "unit_type": "gpu_seconds",
+    "price": 4.2,
+    "model": "runwayml/stable-diffusion-v1-5",
+    "prompt_hash": "sha256:cf1f...",
+    "started_at": 1695720000,
+    "completed_at": 1695720002,
+    "artifact_hash": "sha256:deadbeef...",
+    "coordinator_id": "coord-eu-west-1",
+    "nonce": "b7f3d10b",
+    "chain_id": 12345
+  },
+  "canonical": "{\"artifact_hash\":\"sha256:deadbeef...\",\"chain_id\":12345,\"client\":\"ait1clientabc...\",\"completed_at\":1695720002,\"coordinator_id\":\"coord-eu-west-1\",\"job_id\":\"job-abc123\",\"model\":\"runwayml/stable-diffusion-v1-5\",\"nonce\":\"b7f3d10b\",\"price\":4.2,\"prompt_hash\":\"sha256:cf1f...\",\"provider\":\"ait1minerxyz...\",\"receipt_id\":\"rcpt-20250926-000123\",\"started_at\":1695720000,\"unit_type\":\"gpu_seconds\",\"units\":1.9,\"version\":\"1.0\"}",
+  "signature": {
+    "alg": "Ed25519",
+    "key_id": "TJvH0A9pkk0c3uQMNlCivLs3GR3i1T2TtfIbLT0n29Q",
+    "sig": "fSmokpSz5-qf0XwwuBOBNseIONRM3Y6Bmrko4oE6mY0nS_noq_3zQ9y87Cd3IkMct3S5Ve-URC7D8TVBiBkvAg"
+  }
+}