refactor: remove unused UI and execution configuration

Remove unused configuration options that were not consumed by the UI:

- Remove UI configuration (UI_FONT_FAMILY, UI_FONT_SIZE, UI_PRODUCTION_ID_INPUT_WIDTH)
  - No UI components were using these settings
  - Settings page had no inputs for these options

- Remove execution configuration (EXECUTION_DRYRUN)
  - Dry run mode is controlled by Cleaner page UI toggle
  - State is managed via sessionStorage, not config file

Files modified:
- src/main/types/settings.types.ts: Remove UiConfig and ExecutionConfig interfaces
- src/main/services/config/config-manager.ts: Remove config read/write logic
- src/main/ipc/settings-handler.ts: Remove filtered fields

src/main/types/settings.types.ts

@@ -110,26 +110,6 @@ export interface ValidationConfig {
   defaultManager: string
 }
 
-/**
- * UI configuration
- */
-export interface UiConfig {
-  /** Font family */
-  fontFamily: string
-  /** Font size */
-  fontSize: number
-  /** Production ID input width */
-  productionIdInputWidth: number
-}
-
-/**
- * Execution configuration (User-only)
- */
-export interface ExecutionConfig {
-  /** Dry run mode */
-  dryRun: boolean
-}
-
 /**
  * Complete settings data structure
  */
@@ -144,10 +124,6 @@ export interface SettingsData {
   extraction: ExtractionConfig
   /** Validation configuration */
   validation: ValidationConfig
-  /** UI configuration */
-  ui: UiConfig
-  /** Execution configuration */
-  execution: ExecutionConfig
 }
 
 /**