Export Ghidra labels/symbols to VICE

## Description

Push Ghidra labels and function names to VICE's symbol table, so VICE's own built-in monitor displays symbolic names instead of raw hex addresses.

## Proposed implementation

- Read all labels from the current Ghidra program
- Send them to VICE using the monitor's label/symbol commands
- Could use VICE's `add_label` monitor command or write a `.sym` file that VICE can load
- Trigger on connect and optionally on Ghidra label changes

## Why this matters

Users who switch between Ghidra and VICE's built-in monitor would see consistent symbolic names in both tools.