- Add full diplomacy subsystem: tiered gifts (BC payments with diminishing returns), trade agreements (passive BC income, coexists with treaties, cancelled on war), and espionage mission toggles (Off/Steal/Sabotage) in the Audience screen.
- Implement whole-galaxy diplomacy passes: border and fleet proximity tension, fleet intrusion tracking with escalating penalties and force-opened Audience complaints, and "enemy of my enemy" attitude triangulation.
- Update Audience screen UI with new action buttons, gift picker, intelligence toggle, and species-specific chat dialogue for all diplomacy events.
- Add research choice prompts for ambiguous tech frontier picks, surfaced before the turn report.
- Improve star map: Delaunay triangulation for controlled-space range darkness, staggered docked fleet markers, expanded pan slack to clear UI chrome, and zoom-aware colony info labels.
- Backward-compatible save serialization for new diplomacy fields.
- Add comprehensive test coverage for all new logic, chat completeness, and AI soak validation.
