- New docs/ELETTRONICA_BASE.md covering Volt/Ampere/Ohm/Ohm's law,
  frequency/period/duty cycle, components seen up to project 09,
  circuit concepts, digital vs analog, RGB additive synthesis
- Glossary entries linked to relevant ELETTRONICA_BASE sections
- New glossary entries: Ohm, Ohm's law, Polarity, Power, Resistance,
  Resistor, Current, Ampere, Circuit
- README and progression plan updated to reference the new doc

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>