refactor(hub): 手搓 agent loop 换成 Vercel AI SDK

将 provider/runner/tools 三件手搓轮子替换为 AI SDK v7 的 generateText + tool:
- 删 openrouter-provider.ts(翻译层消失)、provider.ts 自定义消息类型
- runner.ts 循环体改为 generateText({stopWhen: stepCountIs}),保留 RunRequest/RunResult 公共签名
- tools.ts ToolRegistry 改为 ToolFactory + build(ctx, names?) 按 role 白名单构建 tools record
- workspace/cph/feishu 工具改写为 tool() 定义,execute 闭包捕获 per-run ToolContext
- transcript.ts 改为 ModelMessage[] JSONL(0.0.0 cutover,无迁移)
- server.ts/trigger.ts 接 modelFactory + toolWhitelist
- 测试:helpers 写 MockLanguageModel implements LanguageModelV4;5 个测试改写 + 新增 runner.test.ts
- 移除未使用的 openai 依赖
- ADR-0017 Consequences 同步:loop 委托给 AI SDK,provider seam 是 LanguageModel

tsc 干净,54 tests 全过。

hub/src/agent/cph.ts

@@ -1,10 +1,10 @@
 /**
- * `cph` subprocess tools — the Hub↔Courseware coupling point.
+ * `cph` subprocess tools - the Hub<->Courseware coupling point.
  *
  * The Hub agent does not parse engineering-file models in-process; it calls the
  * stable `cph` CLI (ADR-0016 version contract). `cph check` validates a
  * project; `cph build` renders a target artifact. Version compatibility is the
- * CLI's responsibility — it refuses incompatible `.cph-version` files with a
+ * CLI's responsibility - it refuses incompatible `.cph-version` files with a
  * `cphVersionMismatch` error diagnostic (ADR-0016); the Hub merely runs the
  * subprocess and returns its stdout/stderr/exit to the model.
  *
@@ -14,7 +14,9 @@
  */
 import { execFile } from "node:child_process";
 import { promisify } from "node:util";
-import type { RegisteredTool } from "./tools.js";
+import { tool } from "ai";
+import { z } from "zod";
+import type { ToolContext, ToolDefinition } from "./tools.js";
 
 const execFileAsync = promisify(execFile);
 
@@ -53,30 +55,19 @@ async function runCph(args: readonly string[], workspaceDir: string): Promise<Ex
   }
 }
 
-interface CphCheckArgs {
-  readonly path?: string;
-}
-
-/// `cph check <dir>` — validate a curriculum engineering file. Returns the
+/// `cph check <dir>` - validate a curriculum engineering file. Returns the
 /// checker's diagnostics (stdout) for the model to act on. Non-zero exit means
 /// the file has error diagnostics (ADR-0010); the output is still returned,
-/// not thrown — the model needs to see the diagnostics to fix them.
-export function cphCheckTool(): RegisteredTool {
-  return {
-    spec: {
-      name: "cph_check",
-      description:
-        "Run `cph check` on the project's curriculum engineering file. Returns diagnostics (7 classes: structure/schema/compile/version…). Non-zero exit means error diagnostics present — read the output to fix them.",
-      parameters: {
-        type: "object",
-        properties: {
-          path: { type: "string", description: "Path to the engineering file dir; defaults to the workspace root." },
-        },
-      },
-    },
-    async execute(args, ctx): Promise<string> {
-      const a = (args as CphCheckArgs) ?? {};
-      const target = a.path ?? ".";
+/// not thrown - the model needs to see the diagnostics to fix them.
+export function cphCheckTool(ctx: ToolContext): ToolDefinition {
+  return tool({
+    description:
+      "Run `cph check` on the project's curriculum engineering file. Returns diagnostics (7 classes: structure/schema/compile/version...). Non-zero exit means error diagnostics present - read the output to fix them.",
+    inputSchema: z.object({
+      path: z.string().describe("Path to the engineering file dir; defaults to the workspace root.").optional(),
+    }),
+    execute: async (args): Promise<string> => {
+      const target = args.path ?? ".";
       const res = await runCph(["check", target], ctx.workspaceDir);
       return JSON.stringify({
         exitCode: res.exitCode,
@@ -84,39 +75,25 @@ export function cphCheckTool(): RegisteredTool {
         stderr: res.stderr,
       });
     },
-  };
+  });
 }
 
-interface CphBuildArgs {
-  readonly target: string;
-  readonly path?: string;
-  readonly output?: string;
-}
-
-/// `cph build <dir> --target <T> -o <out>` — render a target artifact. The
-/// target (student/teacher/…) determines the build (ADR-0009). Output path
+/// `cph build <dir> --target <T> -o <out>` - render a target artifact. The
+/// target (student/teacher/...) determines the build (ADR-0009). Output path
 /// is relative to the workspace unless absolute.
-export function cphBuildTool(): RegisteredTool {
-  return {
-    spec: {
-      name: "cph_build",
-      description:
-        "Run `cph build` to render a curriculum artifact (e.g. student/teacher PDF). Target selects the build; output names the result file.",
-      parameters: {
-        type: "object",
-        properties: {
-          target: { type: "string", description: "Build target, e.g. 'student', 'teacher'." },
-          path: { type: "string", description: "Path to the engineering file dir; defaults to the workspace root." },
-          output: { type: "string", description: "Output file path (relative to workspace or absolute)." },
-        },
-        required: ["target"],
-      },
-    },
-    async execute(args, ctx): Promise<string> {
-      const a = args as CphBuildArgs;
-      const target = a.path ?? ".";
-      const out = a.output ?? `build/${a.target}.pdf`;
-      const res = await runCph(["build", target, "--target", a.target, "-o", out], ctx.workspaceDir);
+export function cphBuildTool(ctx: ToolContext): ToolDefinition {
+  return tool({
+    description:
+      "Run `cph build` to render a curriculum artifact (e.g. student/teacher PDF). Target selects the build; output names the result file.",
+    inputSchema: z.object({
+      target: z.string().describe("Build target, e.g. 'student', 'teacher'."),
+      path: z.string().describe("Path to the engineering file dir; defaults to the workspace root.").optional(),
+      output: z.string().describe("Output file path (relative to workspace or absolute).").optional(),
+    }),
+    execute: async (args): Promise<string> => {
+      const target = args.path ?? ".";
+      const out = args.output ?? `build/${args.target}.pdf`;
+      const res = await runCph(["build", target, "--target", args.target, "-o", out], ctx.workspaceDir);
       return JSON.stringify({
         exitCode: res.exitCode,
         stdout: res.stdout,
@@ -124,5 +101,5 @@ export function cphBuildTool(): RegisteredTool {
         output: out,
       });
     },
-  };
+  });
 }