The first version of Diplomacy is now available. I put this off for quite a while and wanted to have it in before expanding the game further. Basic war declarations, friendly and non aggression pacts can be signed. AI empires no longer attack when relations are neutral, though combat can still occur between neutral empires, war must be declared beforehand or is declared automatically when sending a fleet with System Control role in another empire's territory. Players can also see a fleet GV estimate for other empires, and two new techs have been added to the research panel which improve the frequency and estimation resolution.
Changes:
diplomacy options available in a new panel
spy/trader network territory reveal of another empire's territory is slower and limited to 1 or 2 tiles, improved by unlocking specific techs
option to disable quest(s)
changes to how the AI expands the IRG network, it should no longer lock itself from expanding by spamming IRG connections
various performance improvements, among them: game map runs in a separate thread, and while not completely smooth due to the GIL, panning the map is much improved while turns progress automatically
fixed a fleet scanning bug: scanning the for the QPS origin tile with fleets didn't work the same way as scanning with a telescope array
fixed combat panel not opening when engaging both ODS and fleets
Will try to get another update soon to expand on quests and other systems that are still hidden and incomplete.