Replace implicit pcs.tmp trace range lookup with explicit plugin configuration

[JoGei]

• InstructionTracer reads pcs.tmp from the process working directory.
• This couples tracing to cwd and hidden file setup.
• XValid users runners must currently create pcs.tmp before simulation.
• Add explicit plugin configuration such as:
  • plugin.gts.pc_range_path
  • or plugin.gts.low_pc
  • plugin.gts.high_pc
• Keep pcs.tmp as fallback only if needed for compatibility.