Restore redundant cd rejection in bash tool

Reverted from educational note back to rejection behavior. When a command tries
to cd into the current working directory (e.g., 'cd /workspace && command'), the
bash tool now rejects it with a clear error message.

Changes:
- Replaced educational note with redundant cd detection and rejection
- Uses runtime.normalizePath() for cross-runtime path comparison
- Works correctly for both local and SSH runtimes
- Updated tests to verify rejection behavior

Author: ammar-agent

src/services/tools/bash.test.ts

@@ -1173,7 +1173,7 @@ describe("SSH runtime redundant cd detection", () => {
     };
   }
 
-  it("should add educational note when command starts with cd", async () => {
+  it("should reject redundant cd when command cds to working directory", async () => {
     const remoteCwd = "/remote/workspace/project/branch";
     using testEnv = createTestBashToolWithSSH(remoteCwd);
     const tool = testEnv.tool;
@@ -1185,27 +1185,33 @@ describe("SSH runtime redundant cd detection", () => {
 
     const result = (await tool.execute!(args, mockToolCallOptions)) as BashToolResult;
 
-    // Command should execute (not blocked)
-    // But should include a note about cd behavior
-    if (result.success && "note" in result) {
-      expect(result.note).toContain("bash command starts in");
-      expect(result.note).toContain("do not persist");
+    // Should reject the redundant cd
+    expect(result.success).toBe(false);
+    if (!result.success) {
+      expect(result.error).toContain("Redundant cd to working directory");
+      expect(result.error).toContain("no cd needed");
+      expect(result.exitCode).toBe(-1);
     }
   });
 
-  it("should not add note when command does not start with cd", async () => {
+  it("should allow cd to different directory", async () => {
     const remoteCwd = "/remote/workspace/project/branch";
     using testEnv = createTestBashToolWithSSH(remoteCwd);
     const tool = testEnv.tool;
 
     const args: BashToolArgs = {
-      script: "echo test",
+      script: "cd /tmp && echo test",
       timeout_secs: 5,
     };
 
     const result = (await tool.execute!(args, mockToolCallOptions)) as BashToolResult;
 
-    // Should not have a note field
-    expect(result).not.toHaveProperty("note");
+    // Should not be blocked (cd to a different directory is allowed)
+    // Note: Test runs locally so actual cd might fail, but we check it's not rejected
+    expect(result.exitCode).not.toBe(-1); // Not a rejection (-1)
+    if (!result.success) {
+      // If it failed, it should not be due to redundant cd detection
+      expect(result.error).not.toContain("Redundant cd");
+    }
   });
 });

src/services/tools/bash.ts

@@ -76,11 +76,25 @@ export const createBashTool: ToolFactory = (config: ToolConfiguration) => {
       let displayTruncated = false; // Hit 16KB display limit
       let fileTruncated = false; // Hit 100KB file limit
 
-      // Detect if command starts with cd - we'll add an educational note for the agent
-      const scriptStartsWithCd = /^\s*cd\s/.test(script);
-      const cdNote = scriptStartsWithCd
-        ? `Note: Each bash command starts in ${config.cwd}. Directory changes (cd) do not persist between commands.`
-        : undefined;
+      // Detect redundant cd to working directory
+      // Match patterns like: "cd /path &&", "cd /path;", "cd '/path' &&", "cd \"/path\" &&"
+      const cdPattern = /^\s*cd\s+['"]?([^'";&|]+)['"]?\s*[;&|]/;
+      const match = cdPattern.exec(script);
+      if (match) {
+        const targetPath = match[1].trim();
+        // Normalize paths for comparison using runtime's path resolution
+        const normalizedTarget = config.runtime.normalizePath(targetPath, config.cwd);
+        const normalizedCwd = config.runtime.normalizePath(".", config.cwd);
+
+        if (normalizedTarget === normalizedCwd) {
+          return {
+            success: false,
+            error: `Redundant cd to working directory detected. The tool already runs in ${config.cwd} - no cd needed. Remove the 'cd ${targetPath}' prefix.`,
+            exitCode: -1,
+            wall_duration_ms: 0,
+          };
+        }
+      }
 
       // Execute using runtime interface (works for both local and SSH)
       const execStream = await config.runtime.exec(script, {
@@ -377,7 +391,6 @@ export const createBashTool: ToolFactory = (config: ToolConfiguration) => {
                   output,
                   exitCode: 0,
                   wall_duration_ms,
-                  ...(cdNote && { note: cdNote }),
                   truncated: {
                     reason: overflowReason ?? "unknown reason",
                     totalLines: lines.length,
@@ -465,7 +478,6 @@ File will be automatically cleaned up when stream ends.`;
               output: lines.join("\n"),
               exitCode: 0,
               wall_duration_ms,
-              ...(cdNote && { note: cdNote }),
             });
           } else {
             resolveOnce({