fix(settings): add fault tolerance and robust defaults for corrupted config files (#346)

- Remove unused comment in ThemeCustomizer.tsx
- Fix Theme import in ThemePreview.tsx (use type-only import)
- Enhance loadSettings in SettingsContext.tsx:
  - Validate loaded settings have required structure
  - Deep merge with DEFAULT_SETTINGS for missing nested sections
  - Fall back to default settings when loading fails (e.g., corrupted config)
  - Add console error logging for debugging

These changes ensure the GUI remains functional even when config files
are corrupted or missing, preventing 'Cannot read properties of undefined'
errors.

Co-authored-by: Droid Agent <droid@factory.ai>

Author: echobt

cortex-gui/src/components/settings/ThemeCustomizer.tsx

@@ -9,7 +9,6 @@ import {
   TERMINAL_COLOR_TOKENS,
 } from "@/context/ThemeContext";
 import { SectionHeader, Button } from "./FormComponents";
-// tokens imported for future use
 
 // ============================================================================
 // Types

cortex-gui/src/components/settings/ThemePreview.tsx

@@ -1,7 +1,7 @@
 import { createSignal, createMemo, onCleanup, For, Show, batch } from "solid-js";
+import type { Theme } from "@/context/ThemeContext";
 import {
   useTheme,
-  Theme,
   DEFAULT_DARK_COLORS,
   DEFAULT_LIGHT_COLORS,
 } from "@/context/ThemeContext";

cortex-gui/src/context/SettingsContext.tsx

@@ -1144,15 +1144,39 @@ export function SettingsProvider(props: ParentProps) {
     });
     try {
       const loaded = await invoke<CortexSettings>("settings_load");
+      // Validate loaded settings have required structure, fallback to defaults for missing sections
+      const validated: CortexSettings = {
+        ...DEFAULT_SETTINGS,
+        ...loaded,
+        // Ensure nested objects have defaults merged properly
+        editor: { ...DEFAULT_SETTINGS.editor, ...loaded?.editor },
+        theme: { ...DEFAULT_SETTINGS.theme, ...loaded?.theme },
+        terminal: { ...DEFAULT_SETTINGS.terminal, ...loaded?.terminal },
+        ai: { ...DEFAULT_SETTINGS.ai, ...loaded?.ai },
+        security: { ...DEFAULT_SETTINGS.security, ...loaded?.security },
+        files: { ...DEFAULT_SETTINGS.files, ...loaded?.files },
+        explorer: { ...DEFAULT_SETTINGS.explorer, ...loaded?.explorer },
+        zenMode: { ...DEFAULT_SETTINGS.zenMode, ...loaded?.zenMode },
+        screencastMode: { ...DEFAULT_SETTINGS.screencastMode, ...loaded?.screencastMode },
+        search: { ...DEFAULT_SETTINGS.search, ...loaded?.search },
+        debug: { ...DEFAULT_SETTINGS.debug, ...loaded?.debug },
+        git: { ...DEFAULT_SETTINGS.git, ...loaded?.git },
+        http: { ...DEFAULT_SETTINGS.http, ...loaded?.http },
+        commandPalette: { ...DEFAULT_SETTINGS.commandPalette, ...loaded?.commandPalette },
+        workbench: { ...DEFAULT_SETTINGS.workbench, ...loaded?.workbench, editor: { ...DEFAULT_SETTINGS.workbench.editor, ...loaded?.workbench?.editor } },
+      };
       batch(() => {
-        setWsState("userSettings", reconcile(loaded));
+        setWsState("userSettings", reconcile(validated));
         setState("isDirty", false);
       });
     } catch (e) {
       const msg = e instanceof Error ? e.message : String(e);
+      console.error("[SettingsContext] Failed to load settings, using defaults:", msg);
       batch(() => {
         setState("error", msg);
         setWsState("error", msg);
+        // Fall back to default settings when loading fails (e.g., corrupted config file)
+        setWsState("userSettings", reconcile({ ...DEFAULT_SETTINGS }));
       });
     } finally {
       batch(() => {