Add the QGraphicsView layer: NodeItem (SVG symbol + title + draggable,
snap-to-grid), PortItem (relation-colored anchors with compatibility
hints), EdgeItem (orthogonal routing, arc hops on crossings, line styles,
head/tail decorations, animated flow dashes), and DiagramScene binding the
document to items with edge-drawing interaction and a grid background.
Add EditorController with a QUndoStack (add/connect/delete/move/edit) and
scene interaction tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Add observable AppConfig (grid/snap/arc-on-crossing/animation/theme),
pure-geometry orthogonal router with grid-snapped bends and perpendicular
crossing detection for arc hops, and a mock flow-distribution solver that
pushes supply to demand along shortest paths and records signed per-edge
flow and direction. Covered by routing and flow-solver tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Set up PyQt6 + QGraphicsView pipeline-editor skeleton, requirements,
pytest headless config, and the actionable implementation plan under
docs/plan.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
