refactor(platform): replace platform checks with capability-based system

- Add PlatformCapabilities interface to define available features
- Remove isWeb(), isCapacitor(), isElectron(), isPyWebView() methods
- Update platform services to implement getCapabilities()
- Refactor DataExportSection to use capability checks instead of platform checks
- Improve platform abstraction and separation of concerns
- Make platform-specific logic more maintainable and extensible

This change decouples components from specific platform implementations,
making the codebase more maintainable and easier to extend with new platforms.

src/services/platforms/PyWebViewPlatformService.ts

@@ -1,4 +1,4 @@
-import { ImageResult, PlatformService } from "../PlatformService";
+import { ImageResult, PlatformService, PlatformCapabilities } from "../PlatformService";
 import { logger } from "../../utils/logger";
 
 /**
@@ -15,6 +15,21 @@ import { logger } from "../../utils/logger";
  * - Python-JavaScript bridge functionality
  */
 export class PyWebViewPlatformService implements PlatformService {
+  /**
+   * Gets the capabilities of the PyWebView platform
+   * @returns Platform capabilities object
+   */
+  getCapabilities(): PlatformCapabilities {
+    return {
+      hasFileSystem: false, // Not implemented yet
+      hasCamera: false, // Not implemented yet
+      isMobile: false,
+      isIOS: false,
+      hasFileDownload: false, // Not implemented yet
+      needsFileHandlingInstructions: false
+    };
+  }
+
   /**
    * Reads a file using the Python backend.
    * @param _path - Path to the file to read
@@ -80,38 +95,6 @@ export class PyWebViewPlatformService implements PlatformService {
     throw new Error("Not implemented");
   }
 
-  /**
-   * Checks if running on Capacitor platform.
-   * @returns false, as this is not Capacitor
-   */
-  isCapacitor(): boolean {
-    return false;
-  }
-
-  /**
-   * Checks if running on Electron platform.
-   * @returns false, as this is not Electron
-   */
-  isElectron(): boolean {
-    return false;
-  }
-
-  /**
-   * Checks if running on PyWebView platform.
-   * @returns true, as this is the PyWebView implementation
-   */
-  isPyWebView(): boolean {
-    return true;
-  }
-
-  /**
-   * Checks if running on web platform.
-   * @returns false, as this is not web
-   */
-  isWeb(): boolean {
-    return false;
-  }
-
   /**
    * Should handle deep link URLs through the Python backend.
    * @param _url - The deep link URL to handle