Track: some flow boards render broken (tangled layout / edges over nodes)

[ivanmkc]

Tracking issue for broken flow-chart rendering.

Some pushed flow boards render hard to read — a tangled layout and/or edges routed over or across nodes. This is the tracker for hardening flow rendering so these lay out cleanly.

Next steps

• Reproduce on an affected board (repro held privately — no environment, workspace, or project details here).
• Investigate the dagre layout params / edge routing and extend the geometry-lint so these cases are caught and laid out readably (cf. prior work in feat(viewer): iOS safe-area insets (viewport-fit=cover) — needs real-device test #131–fix(viewer): readable flow zoom floor on phones (M6) — needs on-device feel check #133).

No identifying details included by design.

[ivanmkc]

2026-08-29 triage: keep this open as a P1 rendering defect until the private board can be replayed. Since the original Dagre-era report, SGCR routing, grouped layout, geometry checks, overlap guards, and measured-node repass work have landed through #286–#300. The public shipped-case overlap suite is green, but that is not evidence that the private reproduction is fixed. Next action is to replay that board on current master and reduce any remaining failure to a sanitized fixture.

[ivanmkc]

Implemented the grouped-geometry cleanup as a stacked series on top of #305:

• Construct grouped tiers from measured geometry #306 — measured tier construction, standardized parent/member/label spacing, explicit face-center anchors, atomic reveal, patch remeasurement, reserved edge-label channels
• Construct compact zones from measured geometry #307 — measured compact zones across data-lineage/ETL/infra/Kubernetes/long-label cases
• Construct swimlanes from measured geometry #308 — measured swimlanes, strict render-error detection, start-anchored long LR/default-direction lanes

Verification on the top of stack: 1,064 tests passed (18 skipped); production build passed; twice-rendered gallery sweep is 32/32 clean with 0 known-bad and 0 regressions; dedicated painted-DOM checks report no node/container overlap, spillout, anchor mismatch, or edge-over-node crossing. The local viewer is redeployed from #308 on port 8080 with architecture, zone, and swimlane boards republished.

[ivanmkc]

Follow-up visual-rhythm work is now in stacked PR #309: shared tier widths, compact zone channels, measured swimlane rank packing, deterministic typography, and refreshed before/after screenshots. Verification: viewer 790/790, overlap corpus 32/32 clean, and painted grouped geometry clean in all three modes.