feat(agent): unify models and validate OpenCode providers

Generate chat, task and learning models from agent-models.json.
Use WaterNetwork fast/expert models with 272k context and validate
upstream names before readiness. Add an isolated model check command
with signal-safe cleanup and plugin, Skill and MCP management docs.

Verified in isolation: type checks, 26 focused tests and both model
catalog checks; no model inference requests.

.opencode/agent-plugin.json

@@ -0,0 +1,49 @@
+{
+  "schema_version": 1,
+  "id": "tjwater.supply-agent",
+  "name": "TJWater 供水 Agent",
+  "description": "供水 Agent 的指令、OpenCode 插件、Skill 与外部 MCP 管理索引。",
+  "purpose": "documentation-index",
+  "path_base": ".opencode",
+  "runtime": {
+    "name": "opencode2",
+    "config_builder": "../src/runtime/opencode2-config.ts"
+  },
+  "agents": [
+    {
+      "id": "instruction",
+      "description": "编排供水数据查询、地图展示和工况任务，遵守类型化工具与业务证据边界。",
+      "path": "agents/instruction.md",
+      "mode": "primary"
+    }
+  ],
+  "plugins": [
+    {
+      "id": "tjwater.tools",
+      "description": "注册业务工具和待办工具，安装会话 Shell 沙箱与 MCP 权限策略，并提供模型校验和工具发现 RPC。",
+      "package": "tjwater-plugin",
+      "entrypoint": "tjwater-plugin/index.ts",
+      "implementation": "plugins/tjwater-tools.ts"
+    }
+  ],
+  "skills": {
+    "description": "部署实例的可复用流程和辅助文件，由 skill_manager 经可信内部工具桥维护。",
+    "default_root": "skills",
+    "root_env": "OPENCODE_SKILLS_ROOT_DIR",
+    "entry_file": "SKILL.md",
+    "manager_tool": "skill_manager",
+    "store": "../src/skills/store.ts"
+  },
+  "mcp": {
+    "description": "管理员配置的远程 HTTP 或本地 stdio 连接，执行时按会话类型应用权限策略。",
+    "config_file": "../opencode.json",
+    "config_key": "mcp.servers",
+    "override_env": "OPENCODE_CONFIG_CONTENT",
+    "policy": "mcp-policy.ts",
+    "status_endpoint": "/api/v1/agent/chat/session/:session_id/mcp"
+  },
+  "models": {
+    "config_file": "../agent-models.json",
+    "override_env": "AGENT_MODEL_CONFIG_PATH"
+  }
+}