feat: implement MACP phase 1 core protocol

tools/orchestrator-matrix/protocol/task.schema.json

@@ -23,14 +23,85 @@
       "enum": [
         "pending",
         "running",
+        "gated",
         "completed",
-        "failed"
+        "failed",
+        "escalated"
       ]
     },
+    "type": {
+      "type": "string",
+      "enum": [
+        "coding",
+        "deploy",
+        "research",
+        "review",
+        "documentation",
+        "infrastructure"
+      ],
+      "description": "Task type - determines dispatch strategy and gate requirements"
+    },
+    "dispatch": {
+      "type": "string",
+      "enum": [
+        "yolo",
+        "acp",
+        "exec"
+      ],
+      "description": "Execution backend: yolo=mosaic yolo (full system), acp=OpenClaw sessions_spawn (sandboxed), exec=direct shell"
+    },
     "runtime": {
       "type": "string",
       "description": "Preferred worker runtime, e.g. codex, claude, opencode"
     },
+    "worktree": {
+      "type": "string",
+      "description": "Path to git worktree for this task, e.g. ~/src/repo-worktrees/task-042"
+    },
+    "branch": {
+      "type": "string",
+      "description": "Git branch name for this task"
+    },
+    "brief_path": {
+      "type": "string",
+      "description": "Path to markdown task brief relative to repo root"
+    },
+    "result_path": {
+      "type": "string",
+      "description": "Path to JSON result file relative to .mosaic/orchestrator/"
+    },
+    "issue": {
+      "type": "string",
+      "description": "Issue reference (e.g. #42)"
+    },
+    "pr": {
+      "type": [
+        "string",
+        "null"
+      ],
+      "description": "PR number/URL once opened"
+    },
+    "depends_on": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      },
+      "description": "List of task IDs this task depends on"
+    },
+    "max_attempts": {
+      "type": "integer",
+      "minimum": 1,
+      "default": 1
+    },
+    "attempts": {
+      "type": "integer",
+      "minimum": 0,
+      "default": 0
+    },
+    "timeout_seconds": {
+      "type": "integer",
+      "description": "Override default timeout for this task"
+    },
     "command": {
       "type": "string",
       "description": "Worker command to execute for this task"