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.

src/runtime/opencode.ts

@@ -8,6 +8,8 @@ import { realpath, rm } from "node:fs/promises";
 import { createConversationWorkspace, resolveConversationWorkspace } from "./conversationWorkspace.js";
 import { serviceOpencodeConfig } from "./opencode2-config.js";
 import { mcpReadonlyTools, mcpRuntimeReportSchema } from "./mcp-config.js";
+import { parseModelReference } from "../chat/modelConfig.js";
+import { assertModelCheckPassed, modelCheckReportSchema, modelCheckTargets } from "./model-check.js";
 
 import { config } from "../config.js";
 import { logger } from "../logger.js";
@@ -127,6 +129,14 @@ export class OpencodeRuntimeAdapter {
     return selected;
   }
 
+  async checkModels(directory = process.cwd()) {
+    const client = await this.ensureClient();
+    const response = await client.rpc.call({
+      rpcID: "tjwater.tools", method: "check_models", input: modelCheckTargets(config.MODEL_CONFIG), location: { directory },
+    }, { signal: AbortSignal.timeout(30_000) });
+    return modelCheckReportSchema.parse(response.output);
+  }
+
   async warmup(): Promise<void> {
     const client = await this.ensureClient();
     const health = await this.health();
@@ -148,6 +158,7 @@ export class OpencodeRuntimeAdapter {
       if (!actualRoot || await realpath(actualRoot) !== await realpath(config.CONVERSATION_WORKSPACE_ROOT)) throw new Error("OpenCode and Agent conversation workspace roots do not match");
       const mcp = await this.readMcpReport(client, session.location.directory);
       if (mcp.configuration_errors.length) throw new Error("MCP configuration invalid");
+      assertModelCheckPassed(await this.checkModels(session.location.directory));
       const models = await client.model.list({ location: { directory: session.location.directory } });
       const model = models.data.find((model) => `${model.providerID}/${model.id}` === config.OPENCODE_MODEL);
       if (!model?.enabled || !model.capabilities.tools) {
@@ -162,7 +173,7 @@ export class OpencodeRuntimeAdapter {
 
   async createSession(title?: string) {
     const client = await this.ensureClient();
-    const [providerID, id] = config.OPENCODE_MODEL.split("/");
+    const { providerID, modelID: id } = parseModelReference(config.OPENCODE_MODEL);
     const directory = await createConversationWorkspace(config.CONVERSATION_WORKSPACE_ROOT);
     try {
       return await client.session.create({ title, agent: "instruction", model: { providerID, id }, location: { directory } });
@@ -468,12 +479,7 @@ export class OpencodeRuntimeAdapter {
 export const opencodeRuntime = new OpencodeRuntimeAdapter();
 
 function buildOpencodeConfig(): Record<string, unknown> {
-  return serviceOpencodeConfig(deepMerge(
-    deepMerge(readProjectOpencodeConfig(), readEnvOpencodeConfig()),
-    {
-      model: config.OPENCODE_MODEL,
-    },
-  ));
+  return serviceOpencodeConfig(deepMerge(readProjectOpencodeConfig(), readEnvOpencodeConfig()), config.MODEL_CONFIG);
 }
 
 function readProjectOpencodeConfig(): Record<string, unknown> {