fix(cpgrid): reject out-of-segment crossing nodes

[tomerarnon]

Summary

This changes corner-point grid crossing-node construction to treat line intersections as bounded segment intersections.

Previously, find_crossing_node used the intersection of the infinite lines defined by two CPG face edges. For nearly parallel or strongly skewed edges, that can produce an extra node far outside the local grid geometry. The new logic:

• computes segment parameters for both edges
• rejects intersections outside either segment
• keeps a small tolerance for floating-point endpoint overshoot
• skips adding a crossing node when no bounded crossing exists

Tests

• added unit coverage for an interior crossing
• added unit coverage for a tiny endpoint overshoot
• added unit coverage for a near-parallel out-of-segment case

[tomerarnon]

Here is a minimal reproducer for the crossing-node issue using find_crossing_node directly.

using GeoEnergyIO
import GeoEnergyIO.CornerPointGrid: find_crossing_node

x1 = [517.2413793103449, 827.5862068965517, 832.5650700477282]
x2 = [517.2413793103449, 775.8620689655172, 843.7944466341665]
x3 = [517.2413793103449, 827.5862068965517, 833.565070047728]
x4 = [517.2413793103449, 775.8620689655172, 844.7944461223784]

pt = find_crossing_node(x1, x2, x3, x4)
println(pt)

The four points define two finite CPG edge segments. Their local envelope is:

y = 775.8620689655172 .. 827.5862068965517
z = 832.5650700477282 .. 844.7944461223784

Package output before this change:

[517.2413793103449, -1.010647461257371e8, 2.1942298049696658e7]

That point is far outside the finite segment envelope. The corresponding segment parameter is:

t = 1.9539344250975822e6

Package output with this PR:

nothing

Visual summary: