feat(pi-subagents): 重新启用子 Agent 并使用独立的子 Agent 提示词

- 根包恢复 file:./pi-subagents 依赖与 extensions/subagents.ts 加载
  （排在 permission-system 之后、Tool Search 之前），并刷新根锁文件；
  Agent / get_subagent_result / steer_subagent 权限设为 allow，
  子 Agent 内的实际操作仍逐个经权限系统并转发主会话。
- 新增 config/prompt/subagent/：执行者角色 preamble 与组合包自带的
  general-purpose / Explore / Plan 定义（替换上游内置，去掉 bash find
  冲突规则与写死的 Haiku 模型）。
- pi-subagents 新增 basePrompt / bundledAgentsDir / excludedExtensionPaths
  选项：子 Agent 不再嵌入父会话提示词，身份标记置于开头；子会话排除
  pi-ask-user。未传选项时保持上游行为。
- system-prompt.ts：customPrompt 自带开场白时不再覆盖（修复子 Agent 角色
  与 <active_agent> 身份被抹掉）；仅凭 customPrompt 上的 <active_agent>
  识别子会话，routing 规则支持 scope，sections 支持 subagentExclude
  （子会话去掉 memory_policy 与 chrome_profile_bridge）。
- pi-hermes-memory：子会话只读，记忆/skill 写入工具返回错误，后台整理、
  纠错检测、会话 flush 与索引写入全部跳过。

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

tests/system-prompt.test.ts

@@ -9,6 +9,7 @@ import { fileURLToPath } from "node:url";
 
 import {
 	applyToolCatalog,
+	isSubagentCustomPrompt,
 	loadRoutingRules,
 	loadSectionsConfig,
 	loadToolCatalog,
@@ -18,6 +19,8 @@ import {
 	resolvePreamblePath,
 	spliceCover,
 	stripJsoncComments,
+	validateRoutingConfig,
+	validateSectionsConfig,
 	type MutablePromptOptions,
 	type RoutingRule,
 } from "../extensions/system-prompt-config.ts";
@@ -74,6 +77,40 @@ test("config/prompt files load with the expected shapes", () => {
 		"chrome_profile_bridge",
 		"tool_routing",
 	]);
+	assert.deepEqual(sections.subagentExclude, ["memory_policy", "chrome_profile_bridge"]);
+});
+
+test("routing scope validation: main/subagent accepted, other values rejected", () => {
+	assert.doesNotThrow(() =>
+		validateRoutingConfig({
+			version: 1,
+			rules: [
+				{ text: "both" },
+				{ scope: "main", text: "m" },
+				{ scope: "subagent", text: "s" },
+			],
+		}),
+	);
+	assert.throws(
+		() => validateRoutingConfig({ version: 1, rules: [{ scope: "everyone", text: "x" }] }),
+		/scope must be "main" or "subagent"/,
+	);
+});
+
+test("sections.jsonc validation: subagentExclude defaults to [] and rejects bad shapes", () => {
+	assert.deepEqual(validateSectionsConfig({ version: 1, order: ["tool_routing"] }), {
+		version: 1,
+		order: ["tool_routing"],
+		subagentExclude: [],
+	});
+	assert.throws(
+		() => validateSectionsConfig({ version: 1, order: [], subagentExclude: "memory_policy" }),
+		/subagentExclude.*array of section names/,
+	);
+	assert.throws(
+		() => validateSectionsConfig({ version: 1, order: [], subagentExclude: ["Bad Name"] }),
+		/not a valid section name/,
+	);
 });
 
 test("readPreamble reads the bundle preamble from config/prompt/", () => {
@@ -185,6 +222,40 @@ test("renderRouting honours whenAll, whenAny and unconditional rules", () => {
 	assert.equal(renderRouting([], ["a"]), "");
 });
 
+test("renderRouting filters scoped rules by audience, unscoped rules render for both", () => {
+	const rules: RoutingRule[] = [
+		{ text: "both audiences" },
+		{ scope: "main", text: "main only" },
+		{ scope: "subagent", text: "subagent only" },
+	];
+
+	assert.equal(renderRouting(rules, undefined, "main"), "- both audiences\n- main only");
+	assert.equal(renderRouting(rules, undefined, "subagent"), "- both audiences\n- subagent only");
+	// The omitted-audience default stays "main" for callers that predate scopes.
+	assert.equal(renderRouting(rules, undefined), "- both audiences\n- main only");
+});
+
+test("isSubagentCustomPrompt matches the <active_agent> contract only on customPrompt", () => {
+	assert.ok(isSubagentCustomPrompt('a\n<active_agent name="Explore"/>'));
+	assert.ok(isSubagentCustomPrompt("<active_agent name='x'/>"));
+	assert.ok(!isSubagentCustomPrompt("plain main-session prompt"));
+	assert.ok(!isSubagentCustomPrompt(undefined));
+	assert.ok(!isSubagentCustomPrompt(42));
+});
+
+test("bundled ssh_connect rules differ per audience", () => {
+	const routing = loadRoutingRules();
+	const tools = ["ssh_connect", "ssh_bash"];
+
+	const main = renderRouting(routing.rules, tools, "main");
+	assert.match(main, /the user explicitly names an imported host/);
+	assert.doesNotMatch(main, /the delegated task explicitly names/);
+
+	const subagent = renderRouting(routing.rules, tools, "subagent");
+	assert.match(subagent, /the delegated task explicitly names an imported host/);
+	assert.doesNotMatch(subagent, /the user explicitly names an imported host/);
+});
+
 test("bundled routing rules select the same guidance the retired tool-routing extension emitted", () => {
 	const routing = loadRoutingRules();
 
@@ -275,12 +346,18 @@ test("spliceCover degenerates to the preamble when the prompt has no sections",
 
 interface FakePromptOptions extends MutablePromptOptions {
 	forceSystemPrompt?: string;
+	customPrompt?: string;
 }
 
 /** Simplified re-render of Pi's prompt from the mutable options object. */
 function renderPiPrompt(options: FakePromptOptions): string {
 	if (options.forceSystemPrompt !== undefined) return options.forceSystemPrompt;
-	const parts = ["PI DEFAULT PREAMBLE"];
+	// Like the real host: a non-empty customPrompt owns the preamble section.
+	const preamble =
+		typeof options.customPrompt === "string" && options.customPrompt.length > 0
+			? options.customPrompt
+			: "PI DEFAULT PREAMBLE";
+	const parts = [preamble];
 	const snippets = Object.entries(options.toolSnippets ?? {});
 	if (snippets.length > 0) {
 		parts.push(`<tools>\n${snippets.map(([n, s]) => `- ${n}: ${s}`).join("\n")}\n</tools>`);
@@ -378,6 +455,86 @@ test("composer degrades to text splicing when an earlier extension froze the pro
 	);
 });
 
+test("composer keeps a customPrompt-owned preamble (subagent / SYSTEM.md) intact", () => {
+	const composer = createSystemPromptComposer();
+	const customPrompt = 'You are the Explore agent.\n<active_agent name="Explore"/>';
+	const options: FakePromptOptions = {
+		customPrompt,
+		selectedTools: ["read"],
+		toolSnippets: { read: "reads files" },
+	};
+	const { ctx } = makeUiCtx();
+	const event = {
+		systemPromptOptions: options,
+		systemPrompt: `${customPrompt}\n\n<tools>\n- read: reads files\n</tools>`,
+	};
+
+	const result = composer.handleBeforeAgentStart(event as never, ctx);
+	const output = result?.systemPrompt ?? "";
+
+	assert.ok(output.startsWith(customPrompt), "the agent's own preamble is kept verbatim");
+	assert.ok(
+		output.includes('<active_agent name="Explore"/>'),
+		"the <active_agent> identity the permission system reads survives",
+	);
+	assert.ok(
+		!output.includes(BUNDLE_PREAMBLE),
+		"the bundle preamble must not be spliced over a customPrompt-owned preamble",
+	);
+	assert.match(output, /<tool_routing>/, "routing still degrades to an appended section");
+});
+
+test("composer treats an <active_agent> customPrompt as a subagent session", () => {
+	const composer = createSystemPromptComposer();
+	const customPrompt =
+		'You are a subagent.\n<active_agent name="Explore"/>\n# Environment\nWorking directory: /work';
+	const options: FakePromptOptions = {
+		customPrompt,
+		selectedTools: ["read", "ssh_connect"],
+		toolSnippets: { read: "reads files", ssh_connect: "connects" },
+		sections: {
+			memory_policy: "memory guidance for main sessions",
+			chrome_profile_bridge: "chrome bridge preamble",
+			remote_ssh: "remote ssh preamble",
+		},
+	};
+	const { ctx } = makeUiCtx();
+
+	const result = composer.handleBeforeAgentStart(makeEvent(options) as never, ctx);
+	const output = result?.systemPrompt ?? "";
+
+	assert.ok(output.startsWith(customPrompt), "the child preamble stays untouched");
+	assert.doesNotMatch(output, /<memory_policy>/, "subagentExclude removes memory_policy");
+	assert.doesNotMatch(output, /<chrome_profile_bridge>/, "subagentExclude removes chrome_profile_bridge");
+	assert.match(output, /<remote_ssh>/, "unexcluded sections are kept");
+	assert.match(output, /the delegated task explicitly names an imported host/, "subagent-scope routing renders");
+	assert.doesNotMatch(output, /the user explicitly names an imported host/, "main-scope routing stays out");
+});
+
+test("a main session keeps excluded sections and main-scope routing even with a literal <active_agent> tag", () => {
+	const composer = createSystemPromptComposer();
+	// The tag appears inside a contributed section (project docs can carry the
+	// literal text) but there is no customPrompt — this is a main session.
+	const options: FakePromptOptions = {
+		selectedTools: ["read", "ssh_connect"],
+		toolSnippets: { read: "reads files", ssh_connect: "connects" },
+		sections: {
+			memory_policy: 'docs mention <active_agent name="Guide"/>',
+			chrome_profile_bridge: "chrome bridge preamble",
+		},
+	};
+	const { ctx } = makeUiCtx();
+
+	const result = composer.handleBeforeAgentStart(makeEvent(options) as never, ctx);
+	const output = result?.systemPrompt ?? "";
+
+	assert.ok(output.startsWith(BUNDLE_PREAMBLE), "the bundle preamble still splices for a main session");
+	assert.match(output, /<memory_policy>/, "main sessions are unaffected by subagentExclude");
+	assert.match(output, /<chrome_profile_bridge>/);
+	assert.match(output, /the user explicitly names an imported host/, "main-scope routing renders");
+	assert.doesNotMatch(output, /the delegated task explicitly names/, "subagent-scope routing stays out");
+});
+
 test("composer falls back to text appends when the host exposes no prompt options", () => {
 	const composer = createSystemPromptComposer();
 	const { ctx } = makeUiCtx();