fix: address review findings — error reporting, Wayland, timeout

- app-lifecycle.ts: emit diagnostic on fire-and-forget app launch
  failure instead of silently swallowing errors
- linux-env.ts: make xdotool on Wayland a hard error instead of
  a broken fallback (xdotool doesn't work on Wayland)
- atspi-bridge.ts: increase Python subprocess timeout from 15s to
  30s for safety on slow/loaded systems with large a11y trees

https://claude.ai/code/session_01H9hrmueNF5pcBM8JeX81mT

Author: claude

src/platforms/linux/app-lifecycle.ts

@@ -1,4 +1,5 @@
 import { runCmd, whichCmd } from '../../utils/exec.ts';
+import { emitDiagnostic } from '../../utils/diagnostics.ts';
 import { sendKey } from './input-actions.ts';
 
 /**
@@ -18,7 +19,13 @@ export async function openLinuxApp(app: string): Promise<void> {
   // Try launching as a binary first
   if (await whichCmd(app)) {
     // Fire-and-forget: apps don't exit when launched
-    runCmd(app, [], { allowFailure: true }).catch(() => {});
+    runCmd(app, [], { allowFailure: true }).catch((err) => {
+      emitDiagnostic({
+        level: 'warn',
+        phase: 'linux_app_launch',
+        data: { app, error: String(err) },
+      });
+    });
     // Give it a moment to start
     await new Promise((resolve) => setTimeout(resolve, 500));
     return;

src/platforms/linux/atspi-bridge.ts

@@ -120,7 +120,7 @@ export async function captureAccessibilityTree(
 
   const result = await runCmd('python3', args, {
     allowFailure: true,
-    timeoutMs: 15_000,
+    timeoutMs: 30_000,
   });
 
   if (result.exitCode !== 0) {

src/platforms/linux/linux-env.ts

@@ -7,7 +7,6 @@
 
 import { whichCmd } from '../../utils/exec.ts';
 import { AppError } from '../../utils/errors.ts';
-import { emitDiagnostic } from '../../utils/diagnostics.ts';
 
 export type DisplayServer = 'wayland' | 'x11';
 export type InputTool = 'xdotool' | 'ydotool';
@@ -39,20 +38,9 @@ export async function ensureInputTool(): Promise<{
       cachedInputTool = { tool: 'ydotool', display };
       return cachedInputTool;
     }
-    if (await whichCmd('xdotool')) {
-      emitDiagnostic({
-        level: 'warn',
-        phase: 'linux_input_tool',
-        data: {
-          message: 'Falling back to xdotool on Wayland. Input synthesis may not work — install ydotool for full Wayland support.',
-        },
-      });
-      cachedInputTool = { tool: 'xdotool', display };
-      return cachedInputTool;
-    }
     throw new AppError(
       'TOOL_MISSING',
-      'ydotool is required for input synthesis on Wayland. Install it via your package manager.',
+      'ydotool is required for input synthesis on Wayland (xdotool does not work on Wayland). Install it via your package manager.',
     );
   }