add bot invocation contracts

contracts/v1/bot-command-invoke-request.json

@@ -0,0 +1,14 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://trixie.invalid/contracts/v1/bot-command-invoke-request.json",
+  "title": "Trixie bot command invocation request",
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["name", "user_id", "permission_level"],
+  "properties": {
+    "name": { "type": "string", "minLength": 1, "maxLength": 64 },
+    "user_id": { "type": "string", "minLength": 1, "maxLength": 64 },
+    "permission_level": { "enum": ["everyone", "subscriber", "moderator", "broadcaster"] },
+    "variables": { "type": "object", "additionalProperties": { "type": "string" } }
+  }
+}

contracts/v1/bot-command-invoke-response.json

@@ -0,0 +1,14 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://trixie.invalid/contracts/v1/bot-command-invoke-response.json",
+  "title": "Trixie bot command invocation response",
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["status", "response", "remaining_cooldown_seconds", "error"],
+  "properties": {
+    "status": { "enum": ["ok", "cooldown", "not_found", "permission_denied", "error"] },
+    "response": { "type": ["string", "null"] },
+    "remaining_cooldown_seconds": { "type": ["integer", "null"], "minimum": 0 },
+    "error": { "type": ["string", "null"] }
+  }
+}

fixtures/v1/bot-command-invoke.response.json

@@ -0,0 +1,6 @@
+{
+  "status": "ok",
+  "response": "Hello Alice",
+  "remaining_cooldown_seconds": null,
+  "error": null
+}