Boundaries.
The persistence boundary (dashed teal) is κucosh(2ρ)cosΦ = γ;
inside the green band the transport amplitude grows (particle-like); outside it decays.
The locking boundary (solid red) is |ω| = κucosh(2ρ);
it is a vertical line at ρ = ±ρL = ±½arccosh(ω/κu), visible only when ω > κu.
Inside the locking boundary the state is dephased (no phase-locked fixed point).
Try dragging ω above κu to see the dephased band open at small ρ.
Fixed points.
When ω ≤ κu: two fixed points at ρ = 0, sinΦ = ω/κu.
The stable node (filled, Φ ≈ arcsin(ω/κu)) is the Constructive attractor
— both branches phase-lock and the amplitude persists;
by the orientation axiom (κu > 0, Reu(AB)|* > 0)
this is the direct observable readout state.
The unstable node (open circle, Φ ≈ π − arcsin(ω/κu)) divides basins.
When ω > κu: the two roots merge onto the locking boundary at Φ = π/2 (degenerate).