- Introduce a dynamic "system" research category built at runtime with two techs: `{System} Map` (granted on entry) and `Unlock {System} Jumpgates` (researchable once every NAV point is discovered).
- Wire gate activation through the research effects seam so completing the jumpgate tech activates the system's gates plus linked return gates, anchors level-1 tethers at each activated gate, and saves/restores via a new `activatedGates` set.
- Extend ResearchModel with optional tree hooks (`available`, `lockNote`) so dynamic categories can gate research on live world state without adding static requires.
- Add map and gate procedural icons, update tests for the new category contract and icon roster, and document the system category in project notes.
