Text size setting for path bar + file list (Compact/Default/Large)

Segmented row in the options popover; applied via data-text on <html> driving
CSS variables (--list-font / --list-meta-font / --path-font), persisted in
settings.json like theme and speed unit.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/shared/types.ts

@@ -44,11 +44,14 @@ export interface ConnectionsFile {
 export interface AppSettings {
 	theme: "system" | "light" | "dark";
 	speedUnit: "MBps" | "Mbps";
+	/** Font size of the path bar and file list. */
+	textSize: "compact" | "default" | "large";
 }
 
 export const DEFAULT_SETTINGS: AppSettings = {
 	theme: "system",
 	speedUnit: "MBps",
+	textSize: "default",
 };
 
 export type TransferState =