Improve script error dialogs #304

- Include the script's directory path #304.
- Exclude Windows-specific instructions on non-Windows OS.
- Standardize language across dialogs for consistency.

Other supporting changes:

- Add script diagnostics data collection from main process.
- Document script file storage and execution tamper protection in
  SECURITY.md.
- Remove redundant comment in `NodeReadbackFileWriter`.
- Centralize error display for uniformity and simplicity.
- Simpify `WindowVariablesValidator` to omit checks when not on the
  renderer process.
- Improve and centralize Electron environment detection.
- Use more emphatic language (don't worry) in error messages.

src/application/ScriptDiagnostics/ScriptDiagnosticsCollector.ts

@@ -0,0 +1,10 @@
+import { OperatingSystem } from '@/domain/OperatingSystem';
+
+export interface ScriptDiagnosticsCollector {
+  collectDiagnosticInformation(): Promise<ScriptDiagnosticData>;
+}
+
+export interface ScriptDiagnosticData {
+  readonly scriptsDirectoryAbsolutePath?: string;
+  readonly currentOperatingSystem?: OperatingSystem;
+}