fix(agent-claude-code): use buildContinuationPrompt for step context

Replace custom buildHistorySummary with shared buildContinuationPrompt
from workflow-agent-kit. This aligns claude-code agent with hermes agent:

- First visit: includes step content (within 32k quota)
- Re-entry: shows only steps since last visit (meta only, session has context)

Previously developer could not see reviewer's detailed feedback on
re-entry, only {"approved":false}. Now gets full review text.

Fixes #486

packages/workflow-agent-claude-code/__tests__/claude-code.test.ts

@@ -39,7 +39,7 @@ describe("buildClaudeCodePrompt", () => {
     expect(result).toContain("## Task\nFix the bug");
   });
 
-  test("includes previous steps as history summary", () => {
+  test("includes previous steps with content on first visit", () => {
     const ctx = makeCtx({
       steps: [
         {
@@ -48,18 +48,50 @@ describe("buildClaudeCodePrompt", () => {
           agent: "hermes",
           detail: "detail-1",
           edgePrompt: "Create a plan.",
+          content: "Here is my detailed plan for doing X.",
         },
       ],
     });
     const result = buildClaudeCodePrompt(ctx);
-    expect(result).toContain("## Previous Steps");
+    expect(result).toContain("## What Happened Since Your Last Turn");
     expect(result).toContain("Step 1: planner");
     expect(result).toContain("do X");
+    // First visit should include step content
+    expect(result).toContain("Here is my detailed plan for doing X.");
+  });
+
+  test("re-entry shows steps since last visit without content", () => {
+    const ctx = makeCtx({
+      isFirstVisit: false,
+      steps: [
+        {
+          role: "developer",
+          output: '{"status":"done"}',
+          agent: "claude-code",
+          detail: "detail-1",
+          edgePrompt: "Implement.",
+          content: "I implemented everything.",
+        },
+        {
+          role: "reviewer",
+          output: '{"approved":false}',
+          agent: "claude-code",
+          detail: "detail-2",
+          edgePrompt: "Review.",
+          content: "Rejected: complexity too high, refactor cmdStepRead.",
+        },
+      ],
+    });
+    const result = buildClaudeCodePrompt(ctx);
+    expect(result).toContain("## What Happened Since Your Last Turn");
+    expect(result).toContain("reviewer");
+    expect(result).toContain("approved");
   });
 
   test("omits history section when steps array is empty", () => {
     const result = buildClaudeCodePrompt(makeCtx({ steps: [] }));
-    expect(result).not.toContain("## Previous Steps");
+    expect(result).not.toContain("## What Happened Since Your Last Turn");
+    expect(result).toContain("## Current Instruction");
   });
 
   test("works without outputFormatInstruction", () => {

packages/workflow-agent-claude-code/src/claude-code.ts

@@ -3,6 +3,7 @@ import type { Store } from "@uncaged/json-cas";
 import {
   type AgentContext,
   type AgentRunResult,
+  buildContinuationPrompt,
   buildRolePrompt,
   createAgent,
   getCachedSessionId,
@@ -18,25 +19,6 @@ const CLAUDE_COMMAND = "claude";
 const CLAUDE_MAX_TURNS = 90;
 const CLAUDE_MODEL = process.env.CLAUDE_MODEL ?? null;
 
-function buildHistorySummary(steps: AgentContext["steps"]): string {
-  if (steps.length === 0) {
-    return "";
-  }
-
-  const lines: string[] = ["## Previous Steps"];
-  for (let i = 0; i < steps.length; i++) {
-    const step = steps[i];
-    if (step === undefined) {
-      continue;
-    }
-    lines.push("");
-    lines.push(`### Step ${i + 1}: ${step.role}`);
-    lines.push(`Output: ${JSON.stringify(step.output)}`);
-    lines.push(`Agent: ${step.agent}`);
-  }
-  return lines.join("\n");
-}
-
 /** Assemble system prompt, task, and prior step outputs for Claude Code. */
 export function buildClaudeCodePrompt(ctx: AgentContext): string {
   const roleDef = ctx.workflow.roles[ctx.role];
@@ -46,11 +28,23 @@ export function buildClaudeCodePrompt(ctx: AgentContext): string {
     parts.push(ctx.outputFormatInstruction, "");
   }
   parts.push(rolePrompt, "", "## Task", ctx.start.prompt);
-  const historyBlock = buildHistorySummary(ctx.steps);
-  if (historyBlock !== "") {
-    parts.push("", historyBlock);
+
+  if (!ctx.isFirstVisit) {
+    // Re-entry (session will be resumed): show only steps since last visit, meta only
+    parts.push("", buildContinuationPrompt(ctx.steps, ctx.role, ctx.edgePrompt));
+  } else if (ctx.steps.length > 0) {
+    // First visit: show all steps with content for recent ones
+    parts.push(
+      "",
+      buildContinuationPrompt(ctx.steps, ctx.role, ctx.edgePrompt, {
+        includeContent: true,
+        quota: 32000,
+      }),
+    );
+  } else {
+    parts.push("", "## Current Instruction", "", ctx.edgePrompt);
   }
-  parts.push("", "## Current Instruction", "", ctx.edgePrompt);
+
   return parts.join("\n");
 }