feat: agent tools as required tools with tenant tool gate

Agent definitions gain tools (websearch/imagegen/playwright,
unknown tool is a 400), stored as agent_tools JSON and returned
by GET /tasks. This is deliberately required-tools, not an
allowlist: create_thread has no tool allowlist and tenant homes
are per-project shared, so blocking other tools cannot be
claimed. Instead the worker fails fast before any model call
when a declared tool has no [mcp_servers.<tool>] section in
the tenant codex-home config.toml (checked after _tenant_dirs
seeding, so a section seeded earlier by another worker counts
as present). The gate runs only for tenant-isolated Docker
workers; local/cloud workers skip it, documented, not verified.

Tests: test_agent_tools.py (8 tests).

cloud/server.py

@@ -1243,6 +1243,8 @@ def migrate_tasks_table(conn):
         "agent_name": "TEXT",
         "agent_version": "TEXT",
         "agent_instructions": "TEXT",
+        # agent 定义 v3：必需工具 JSON 数组（NULL = 未声明）。
+        "agent_tools": "TEXT",
     }
     for name, coltype in new_cols.items():
         if name not in cols:
@@ -1787,6 +1789,20 @@ def _row_get(row, name):
         return None
 
 
+def _agent_tools_from_row(row):
+    """agent_tools 列的容错解析：JSON 数组，非数组/脏数据为 None。"""
+    raw = _row_get(row, "agent_tools")
+    if raw is None:
+        return None
+    if isinstance(raw, list):
+        return list(raw)
+    try:
+        parsed = json.loads(raw)
+    except (TypeError, ValueError):
+        return None
+    return list(parsed) if isinstance(parsed, list) else None
+
+
 def _task_to_dict(row, attachments=None, total_tokens=None):
     depends_on = row["depends_on"]
     try:
@@ -1845,6 +1861,9 @@ def _task_to_dict(row, attachments=None, total_tokens=None):
         "agent_name": _row_get(row, "agent_name"),
         "agent_version": _row_get(row, "agent_version"),
         "agent_instructions": _row_get(row, "agent_instructions"),
+        # v3：agent_tools 存 JSON 数组；脏数据/老行缺列时
+        # 按 None 计，不炸列表接口。
+        "agent_tools": _agent_tools_from_row(row),
         "paused_by_user": _row_get(row, "paused_by_user") or 0,
         "interrupted_reason": _row_get(row, "interrupted_reason"),
         "auto_resume_count": _row_get(row, "auto_resume_count") or 0,
@@ -4360,6 +4379,7 @@ class CloudControlPlaneHandler(BaseHTTPRequestHandler):
                         "description": definition.description,
                         "instructions": definition.instructions,
                         "skills": definition.skills,
+                        "tools": definition.tools,
                         "defaults": definition.defaults,
                     },
                     known_skills=_agent_known_skills())
@@ -4679,6 +4699,8 @@ class CloudControlPlaneHandler(BaseHTTPRequestHandler):
         agent_version_val = definition.version if definition else None
         agent_instructions_val = (
             definition.instructions if definition else None)
+        agent_tools_val = (
+            json.dumps(definition.tools) if definition else None)
         now = time.time()
         conn = self._db()
         try:
@@ -4704,9 +4726,10 @@ class CloudControlPlaneHandler(BaseHTTPRequestHandler):
                     " environment_id, coordinator_parts,"
                     " parent_task_id, coordinator_part,"
                     " child_model, child_effort,"
-                    " agent_name, agent_version, agent_instructions)"
+                    " agent_name, agent_version, agent_instructions,"
+                    " agent_tools)"
                     " VALUES(?, ?, ?, 'queued', ?, ?, ?, ?, ?, ?, NULL, ?,"
-                    " ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+                    " ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
                     (task_id, project_id, prompt, idempotency_key,
                      json.dumps(depends_on), priority, user_id, now, now,
                      executor, goal, verify_command, goal_max_rounds,
@@ -4715,7 +4738,7 @@ class CloudControlPlaneHandler(BaseHTTPRequestHandler):
                      json.dumps(coord_parts) if coord_parts else None,
                      None, None, child_model, child_effort,
                      agent_name_val, agent_version_val,
-                     agent_instructions_val),
+                     agent_instructions_val, agent_tools_val),
                 )
                 # 长任务不限时：API 字段 no_time_limit=1 时写标记，
                 # worker 认领后按不限时跑（单轮 host 600 秒仍在）；