Remove Electron settings panel (breaking change)

- Remove electron/settings/ folder
- Remove config-manager.ts and settings-window.ts
- Remove Configuration menu from app menu
- Remove config-presets IPC handlers
- Update README.md
- Clean up electron.d.ts

Note: This is a breaking change - users will lose existing presets

electron/preload/settings.ts

@@ -1,35 +0,0 @@
-/**
- * Preload script for settings window
- * Exposes APIs for managing configuration presets
- */
-import { contextBridge, ipcRenderer } from "electron"
-
-// Expose settings API to the renderer process
-contextBridge.exposeInMainWorld("settingsAPI", {
-    // Get all presets
-    getPresets: () => ipcRenderer.invoke("config-presets:get-all"),
-
-    // Get current preset ID
-    getCurrentPresetId: () =>
-        ipcRenderer.invoke("config-presets:get-current-id"),
-
-    // Get current preset
-    getCurrentPreset: () => ipcRenderer.invoke("config-presets:get-current"),
-
-    // Save (create or update) a preset
-    savePreset: (preset: {
-        id?: string
-        name: string
-        config: Record<string, string | undefined>
-    }) => ipcRenderer.invoke("config-presets:save", preset),
-
-    // Delete a preset
-    deletePreset: (id: string) =>
-        ipcRenderer.invoke("config-presets:delete", id),
-
-    // Apply a preset (sets environment variables and restarts server)
-    applyPreset: (id: string) => ipcRenderer.invoke("config-presets:apply", id),
-
-    // Close settings window
-    close: () => ipcRenderer.send("settings:close"),
-})