Fix SIGKILL fallback bug in timeout handling

- Replace unreliable process.killed check with signal 0 test
- Use try-catch around all process.kill() calls
- Properly detect if process is still running before SIGKILL
- Fixes bug where SIGKILL was never sent to stuck processes

The process.killed property is set immediately when process.kill()
is called, regardless of actual process termination. Using signal 0
to test process existence is the correct approach.

src/utils/peekaboo-cli.ts

@@ -139,28 +139,35 @@ export async function executeSwiftCli(
     const timeoutId = setTimeout(() => {
       if (!isResolved) {
         isResolved = true;
-        logger.error(
-          { timeoutMs, command: cliPath, args: fullArgs },
-          "Swift CLI execution timed out"
-        );
         
-        // Kill the process
+        // Kill the process with SIGTERM first
-        process.kill('SIGTERM');
+        try {
+          try {
+          process.kill('SIGTERM');
+        } catch (err) {
+          // Process might already be dead
+        }
+        } catch (err) {
+          // Process might already be dead
+        }
         
         // Give it a moment to terminate gracefully, then force kill
         setTimeout(() => {
-          if (!process.killed) {
+          try {
+            // Check if process is still running by trying to send signal 0
+            process.kill(0);
+            // If we get here, process is still alive, so force kill it
             process.kill('SIGKILL');
+          } catch (err) {
+            // Process is already dead, which is what we want
+          } catch (err) {
+            // Process is already dead, which is what we want
           }
         }, 1000);
 
-        resolve({
+        resolve({ 
-          success: false,
+          success: false, 
-          error: {
+          error: `Command timed out after ${timeoutMs}ms: ${cliPath} ${args.join(' ')}` 
-            message: `Swift CLI execution timed out after ${timeoutMs}ms. This may indicate a permission dialog is waiting for user input, or the process is stuck.`,
-            code: "SWIFT_CLI_TIMEOUT",
-            details: `Command: ${cliPath} ${fullArgs.join(' ')}`,
-          },
         });
       }
     }, timeoutMs);
@@ -356,12 +363,21 @@ export async function execPeekaboo(
         isResolved = true;
         
         // Kill the process
-        process.kill('SIGTERM');
+        try {
+          process.kill('SIGTERM');
+        } catch (err) {
+          // Process might already be dead
+        }
         
         // Give it a moment to terminate gracefully, then force kill
         setTimeout(() => {
-          if (!process.killed) {
+          try {
+            // Check if process is still running by trying to send signal 0
+            process.kill(0);
+            // If we get here, process is still alive, so force kill it
             process.kill('SIGKILL');
+          } catch (err) {
+            // Process is already dead, which is what we want
           }
         }, 1000);