fix: use user's terminal font settings for dev server logs

XtermLogViewer was passing DEFAULT_TERMINAL_FONT directly to xterm.js,
but this value is 'default' - a sentinel string for the dropdown selector,
not a valid CSS font family. Also the font size was hardcoded to 13px.

Now reads the user's font preference from terminalState:
- fontFamily: Uses getTerminalFontFamily() to convert to CSS font stack
- defaultFontSize: Uses store value when fontSize prop not provided

Also adds useEffects to update font settings dynamically when they change.

This ensures dev server logs respect Settings > Terminal settings.

apps/ui/src/components/views/board-view/worktree-panel/components/dev-server-logs-panel.tsx

@@ -256,7 +256,6 @@ export function DevServerLogsPanel({
               ref={xtermRef}
               className="h-full"
               minHeight={280}
-              fontSize={13}
               autoScroll={autoScrollEnabled}
               onScrollAwayFromBottom={() => setAutoScrollEnabled(false)}
               onScrollToBottom={() => setAutoScrollEnabled(true)}