feat: serialize keyed tasks across queues with durable fencing tokens

protocol/workerv1/worker.schema.json

@@ -118,6 +118,10 @@
         },
         "cancellation_notifications": {
           "type": "boolean"
+        },
+        "concurrency_keys": {
+          "type": "boolean",
+          "description": "显式支持资源键许可及单调序号交付；同进程重连固定。"
         }
       },
       "required": [
@@ -521,6 +525,12 @@
         "effect_uncertain": {
           "type": "boolean",
           "description": "仍有历史执行效果未核实，重试不清除。"
+        },
+        "concurrency_key": {
+          "type": "string",
+          "minLength": 1,
+          "maxLength": 191,
+          "description": "命名空间内字节精确匹配的互斥资源键；空白边界及控制字符由运行时拒绝。"
         }
       },
       "required": [
@@ -563,6 +573,9 @@
         },
         "server_time": {
           "$ref": "#/$defs/time"
+        },
+        "concurrency_token": {
+          "$ref": "#/$defs/uint64"
         }
       },
       "required": [
@@ -573,7 +586,32 @@
         "lease_until",
         "server_time"
       ],
-      "additionalProperties": false
+      "additionalProperties": false,
+      "allOf": [
+        {
+          "if": {
+            "properties": {
+              "task": {
+                "required": [
+                  "concurrency_key"
+                ]
+              }
+            }
+          },
+          "then": {
+            "required": [
+              "concurrency_token"
+            ]
+          },
+          "else": {
+            "not": {
+              "required": [
+                "concurrency_token"
+              ]
+            }
+          }
+        }
+      ]
     },
     "error": {
       "type": "object",