Struct Connection 

pub struct Connection {
    pub sort: Sort,
    pub unordered: bool,
    pub split_edit_keys: Vec<ColId>,
    pub filters: Option<ConnectionFilters>,
    pub last_pushed_epoch: Cell<u32>,
    pub output: Cell<Option<OutEdge>>,
}

One connection (one downstream output). Self-joins make two. Mirrors Connection (memory-source.ts:75). IDENTICAL shape to 05’s so this module stays backend-agnostic. The mutable bits are Cell so they bump during a push without a &mut borrow held across a vend (foundations §6.2).

Fields

sort: Sort

Resolved order; always the internal sort (sort ?? primaryIndexSort).

unordered: bool

Schema reports sort: None when true; internally sort is the primary index sort, used for overlay PK matching in the unordered path.

split_edit_keys: Vec<ColId>

filters: Option<ConnectionFilters>

last_pushed_epoch: Cell<u32>

Gates overlay visibility (the self-join epoch gate, §3.5).

output: Cell<Option<OutEdge>>