feat(workflow): add thread/edge location support (#558)

Implement thread-level and edge-level working directory management:

- Thread-level cwd (required, defaults to process.cwd())
  - Captured at uwf thread start time
  - Stored in StartNodePayload
  - Inherited by all steps unless overridden

- Edge-level location (optional, supports mustache templates)
  - New location: string | null field on Target type
  - Resolved by moderator using previous step's output
  - Example: location: "{{{repoPath}}}"

- Step audit trail
  - Each StepNodePayload records actual cwd where agent executed

Changes:
- workflow-protocol: Add cwd to StartNodePayload & StepRecord, location to Target
- cli-workflow: Thread start captures cwd, moderator resolves location, step execution uses resolved cwd
- workflow-util-agent: Expose cwd in agent context

Tests:
- Protocol type tests (3 scenarios)
- Moderator location resolution tests (5 scenarios)
- Thread-location integration tests (3 scenarios)

All tests pass. Build successful. Backward compatible.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/workflow-protocol/src/__tests__/types.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, test } from "bun:test";
+import type { StartNodePayload, StepRecord, Target } from "../types.js";
+
+describe("Protocol types for thread/edge location", () => {
+  describe("StartNodePayload", () => {
+    test("has required cwd field", () => {
+      const payload: StartNodePayload = {
+        workflow: "0123456789ABC",
+        prompt: "Test prompt",
+        cwd: "/home/user/project",
+      };
+
+      expect(payload.cwd).toBe("/home/user/project");
+      expect(typeof payload.cwd).toBe("string");
+    });
+  });
+
+  describe("StepRecord", () => {
+    test("has required cwd field", () => {
+      const record: StepRecord = {
+        role: "planner",
+        output: "0123456789ABC",
+        detail: "DEF0123456789",
+        agent: "uwf-hermes",
+        edgePrompt: "Plan the implementation",
+        startedAtMs: Date.now(),
+        completedAtMs: Date.now() + 1000,
+        cwd: "/home/user/project",
+      };
+
+      expect(record.cwd).toBe("/home/user/project");
+      expect(typeof record.cwd).toBe("string");
+    });
+  });
+
+  describe("Target", () => {
+    test("has location field that accepts string", () => {
+      const target: Target = {
+        role: "coder",
+        prompt: "Implement the code",
+        location: "/custom/path",
+      };
+
+      expect(target.location).toBe("/custom/path");
+      expect(typeof target.location).toBe("string");
+    });
+
+    test("has location field that accepts null", () => {
+      const target: Target = {
+        role: "coder",
+        prompt: "Implement the code",
+        location: null,
+      };
+
+      expect(target.location).toBe(null);
+    });
+
+    test("location supports mustache template syntax", () => {
+      const target: Target = {
+        role: "coder",
+        prompt: "Implement the code",
+        location: "{{{repoPath}}}",
+      };
+
+      expect(target.location).toBe("{{{repoPath}}}");
+    });
+  });
+});

packages/workflow-protocol/src/schemas.ts

@@ -20,6 +20,9 @@ const TARGET: JSONSchema = {
   properties: {
     role: { type: "string" },
     prompt: { type: "string" },
+    location: {
+      anyOf: [{ type: "string" }, { type: "null" }],
+    },
   },
   additionalProperties: false,
 };
@@ -49,10 +52,11 @@ export const WORKFLOW_SCHEMA: JSONSchema = {
 export const START_NODE_SCHEMA: JSONSchema = {
   title: "StartNode",
   type: "object",
-  required: ["workflow", "prompt"],
+  required: ["workflow", "prompt", "cwd"],
   properties: {
     workflow: { type: "string", format: "cas_ref" },
     prompt: { type: "string" },
+    cwd: { type: "string" },
   },
   additionalProperties: false,
 };
@@ -60,7 +64,17 @@ export const START_NODE_SCHEMA: JSONSchema = {
 export const STEP_NODE_SCHEMA: JSONSchema = {
   title: "StepNode",
   type: "object",
-  required: ["start", "prev", "role", "output", "detail", "agent", "startedAtMs", "completedAtMs"],
+  required: [
+    "start",
+    "prev",
+    "role",
+    "output",
+    "detail",
+    "agent",
+    "startedAtMs",
+    "completedAtMs",
+    "cwd",
+  ],
   properties: {
     start: { type: "string", format: "cas_ref" },
     prev: {
@@ -73,6 +87,7 @@ export const STEP_NODE_SCHEMA: JSONSchema = {
     edgePrompt: { type: "string" },
     startedAtMs: { type: "integer" },
     completedAtMs: { type: "integer" },
+    cwd: { type: "string" },
   },
   additionalProperties: false,
 };

packages/workflow-protocol/src/types.ts

@@ -18,6 +18,8 @@ export type StepRecord = {
   startedAtMs: number;
   /** Date.now() after agent returns */
   completedAtMs: number;
+  /** Working directory where the agent executed. Missing in legacy nodes → "". */
+  cwd: string;
 };
 
 // ── 4.2 Workflow 定义 ───────────────────────────────────────────────
@@ -34,6 +36,8 @@ export type RoleDefinition = {
 export type Target = {
   role: string;
   prompt: string;
+  /** Optional working directory override via mustache template. */
+  location: string | null;
 };
 
 export type WorkflowPayload = {
@@ -48,6 +52,8 @@ export type WorkflowPayload = {
 export type StartNodePayload = {
   workflow: CasRef;
   prompt: string;
+  /** Working directory where the thread was created. */
+  cwd: string;
 };
 
 export type StepNodePayload = StepRecord & {