feat: runtime manager

game/openapi.yaml

@@ -27,6 +27,8 @@ tags:
     description: Game initialization, state retrieval, and turn advancement.
   - name: PlayerActions
     description: Player command execution, order validation, and turn-report retrieval.
+  - name: Health
+    description: Technical liveness probes used by Runtime Manager and operator tooling.
 paths:
   /api/v1/status:
     get:
@@ -164,6 +166,26 @@ paths:
                 $ref: "#/components/schemas/StateResponse"
         "500":
           $ref: "#/components/responses/InternalError"
+  /healthz:
+    get:
+      tags:
+        - Health
+      operationId: healthz
+      summary: Engine liveness probe
+      description: |
+        Returns `{"status":"ok"}` with HTTP `200` whenever the HTTP server
+        is serving requests, regardless of whether the engine has been
+        initialised through `POST /api/v1/init`. Used by `Runtime Manager`
+        to probe a freshly started container before `init` runs. Carries
+        no game-state semantics; use `GET /api/v1/status` for game-state
+        inspection.
+      responses:
+        "200":
+          description: Engine HTTP server is up.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/HealthzResponse"
 components:
   parameters:
     PlayerParam:
@@ -184,6 +206,17 @@ components:
         minimum: 0
         default: 0
   schemas:
+    HealthzResponse:
+      type: object
+      description: Engine liveness probe response payload.
+      required:
+        - status
+      properties:
+        status:
+          type: string
+          description: Always "ok" while the engine HTTP server is serving requests.
+          enum:
+            - ok
     StateResponse:
       type: object
       description: Summary game state returned after initialization and at each turn boundary.