feat(prompt): 搜索引导改为意图→工具的正向指引，multi_grep 按上游保持关闭

真实会话中模型仍用 bash grep -o | sort -u 做抽取，被拒后直接放弃核对；
原提示词只说"不要"，没告诉它抽取/计数、给程序传文件清单、过滤命令输出时该用什么。

- routing：按已知信息选 grep/find（多变体用 grep 正则 alternation），
  codemode + tools.grep 做聚合，bash 文件清单用 git ls-files，
  overflow_query 过滤输出，被拒后改用替代方案继续
- 权限策略：rg/grep/git grep/find/fd 的 deny 附带指向替代工具的 reason
- tools.jsonc：grep/find 新 snippet，补上 codegraph_explore snippet
- FFF 上游标注 multi_grep 有害：wrapper 删除 PI_FFF_MULTIGREP，清理全部引用
- JSONC 测试改用字符串感知的注释剥离（reason 中含 'src/**/*.ts'）

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

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

tests/system-prompt.test.ts

@@ -255,7 +255,7 @@ test("bundled routing rules select the same guidance the retired tool-routing ex
 	const routing = loadRoutingRules();
 
 	const literal = renderRouting(routing.rules, ["find", "grep", "read"]);
-	assert.match(literal, /Use find to identify likely files or directories/);
+	assert.match(literal, /Pick the local search tool by what you already know/);
 	assert.match(literal, /narrow the path, glob, or pattern instead of increasing the limit/);
 
 	const ssh = renderRouting(routing.rules, ["ssh_connect", "ssh_cd", "ssh_bash"]);
@@ -267,7 +267,7 @@ test("bundled routing rules select the same guidance the retired tool-routing ex
 
 	const minimal = renderRouting(routing.rules, ["read"]);
 	assert.doesNotMatch(minimal, /codegraph_explore first/);
-	assert.doesNotMatch(minimal, /For literal search/);
+	assert.doesNotMatch(minimal, /Pick the local search tool/);
 	assert.doesNotMatch(minimal, /ssh_connect only when/);
 	assert.match(minimal, /Stop searching once the current evidence is sufficient/);
 });
@@ -397,7 +397,6 @@ test("composer splices the preamble, applies the catalog, and orders sections",
 			read: "reads files",
 			bash: "runs commands",
 			edit: "edits",
-			codegraph_explore: "explores",
 			tool_search: "searches",
 		},
 		toolGuidelines: { edit: ["upstream edit rule"] },
@@ -414,6 +413,11 @@ test("composer splices the preamble, applies the catalog, and orders sections",
 		"the bundle preamble replaces Pi's default preamble",
 	);
 	assert.match(output, /<tool_routing>\n- Use codegraph_explore first/);
+	assert.match(
+		output,
+		/<tools>[\s\S]*?- codegraph_explore: Explore code structure from the CodeGraph index/,
+		"tools.jsonc must add a snippet for codegraph_explore, which has no upstream <tools> entry",
+	);
 	assert.match(output, /search files with the find\/grep tools, not bash/);
 	assert.match(output, /LINE#HASH anchors/);
 	assert.ok(