fix(coding-agent): constrained bash cwd auto-detect regex to single-line cd commands

- Updated BashTool's leading `cd` regex to stop matching newline characters so cwd extraction only applies to a single-line `cd ... &&` prefix.
- Added a regression test for multiline commands with a later-line `&&` to ensure each line of the script executes normally.

packages/coding-agent/src/tools/bash.ts

@@ -484,8 +484,10 @@ export class BashTool implements AgentTool<BashToolSchema, BashToolDetails> {
 		const env = normalizeBashEnv(rawEnv);
 
 		// Extract leading `cd <path> && ...` into cwd when the model ignores the cwd parameter.
+		// Constrained to a single line so a `&&` that sits on a later line of a multiline
+		// script can't pull the entire script into the "cwd" capture.
 		if (!cwd) {
-			const cdMatch = command.match(/^cd\s+((?:[^&\\]|\\.)+?)\s*&&\s*/);
+			const cdMatch = command.match(/^cd[ \t]+((?:[^&\\\n\r]|\\.)+?)[ \t]*&&[ \t]*/);
 			if (cdMatch) {
 				cwd = cdMatch[1].trim().replace(/^["']|["']$/g, "");
 				command = command.slice(cdMatch[0].length);

packages/coding-agent/test/tools.test.ts

@@ -1288,6 +1288,23 @@ function b() {
 			);
 		});
 
+		it("should not pull cwd from a later-line `&&` when the command is multiline", async () => {
+			// Regression for #?: the `^cd ... && ...` extractor used `\s` and `[^&\\]`,
+			// which let the lazy match cross newlines and capture the whole script as the
+			// "cwd" when any later line contained `&&`. The model intended `cd` to run as
+			// part of a multiline script, not to relocate the entire command.
+			const command = [
+				"cd /this/directory/definitely/does/not/exist/12345",
+				"echo first-line",
+				"echo second && echo third",
+			].join("\n");
+			const result = await bashTool.execute("test-call-multiline-cd", { command });
+			const output = getTextOutput(result);
+			expect(output).toContain("first-line");
+			expect(output).toContain("second");
+			expect(output).toContain("third");
+		});
+
 		it("should expose background-job tools when bash auto-background is enabled", () => {
 			const autoBackgroundSession = createTestToolSession(
 				testDir,