add http proof

specs/proof_format_http_down_v0.1.json

@@ -0,0 +1,21 @@
+{
+    "timestamp": "2025-04-29T14:03:00Z",
+    "target": "https://api.example.com/health",
+    "status": "down",
+    "http_status_code": null,
+    "latency_ms": null,
+    "error_message": "ENOTFOUND",
+    "observer": {
+      "address": "0xABCD1234EF567890ABCD1234EF567890ABCD1234",
+      "country": "France",
+      "region": "Île-de-France",
+      "city": "Paris",
+      "probe_version": "0.1"
+    },
+    "proof": {
+      "hash": "0xa9b10e75c7d2ddde301c3eb3467c3f9f1db0219f2a7a9f1d6f2c6efc8c7a1b2e",
+      "signature": "0x30450221009ae2cd..."
+    },
+    "version": "0.1"
+  }
+  

specs/proof_format_http_up_v0.1.json

@@ -0,0 +1,21 @@
+{
+    "timestamp": "2025-04-29T14:00:00Z",
+    "target": "https://api.example.com/health",
+    "status": "up",
+    "http_status_code": 200,
+    "latency_ms": 145,
+    "error_message": null,
+    "observer": {
+      "address": "0xABCD1234EF567890ABCD1234EF567890ABCD1234",
+      "country": "France",
+      "region": "Île-de-France",
+      "city": "Paris",
+      "probe_version": "0.1"
+    },
+    "proof": {
+      "hash": "0xf6bca29d0a21c12f45e8c415c8f97d7e5f9b5f4ea37b47f1fcf67f06ce5126e1",
+      "signature": "0x3045022100b5a8e9..."
+    },
+    "version": "0.1"
+  }
+