refactor: unify system prompt runtime params

src/agents/system-prompt.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { buildAgentSystemPrompt } from "./system-prompt.js";
+import { buildAgentSystemPrompt, buildRuntimeLine } from "./system-prompt.js";
 
 describe("buildAgentSystemPrompt", () => {
   it("includes owner numbers when provided", () => {
@@ -252,6 +252,22 @@ describe("buildAgentSystemPrompt", () => {
     expect(prompt).toContain("capabilities=inlineButtons");
   });
 
+  it("includes agent id in runtime when provided", () => {
+    const prompt = buildAgentSystemPrompt({
+      workspaceDir: "/tmp/clawd",
+      runtimeInfo: {
+        agentId: "work",
+        host: "host",
+        os: "macOS",
+        arch: "arm64",
+        node: "v20",
+        model: "anthropic/claude",
+      },
+    });
+
+    expect(prompt).toContain("agent=work");
+  });
+
   it("includes reasoning visibility hint", () => {
     const prompt = buildAgentSystemPrompt({
       workspaceDir: "/tmp/clawd",
@@ -263,6 +279,31 @@ describe("buildAgentSystemPrompt", () => {
     expect(prompt).toContain("/status shows Reasoning");
   });
 
+  it("builds runtime line with agent and channel details", () => {
+    const line = buildRuntimeLine(
+      {
+        agentId: "work",
+        host: "host",
+        os: "macOS",
+        arch: "arm64",
+        node: "v20",
+        model: "anthropic/claude",
+      },
+      "telegram",
+      ["inlineButtons"],
+      "low",
+    );
+
+    expect(line).toContain("agent=work");
+    expect(line).toContain("host=host");
+    expect(line).toContain("os=macOS (arm64)");
+    expect(line).toContain("node=v20");
+    expect(line).toContain("model=anthropic/claude");
+    expect(line).toContain("channel=telegram");
+    expect(line).toContain("capabilities=inlineButtons");
+    expect(line).toContain("thinking=low");
+  });
+
   it("describes sandboxed runtime and elevated when allowed", () => {
     const prompt = buildAgentSystemPrompt({
       workspaceDir: "/tmp/clawd",