Refine workflow edge routing (#507)

* Refine workflow edge routing

Workflow dependency graphs with fan-in/fan-out could still be misleading in
several cases: bends could occur under sibling cards, long horizontal
segments could run through node bodies, and direct upstream dependencies
could appear to terminate at separate nearby merge points. Those patterns
made true dependency relationships harder to read at a glance.

The routing logic now keeps the original Manhattan style by default,
but validates each candidate lane against stricter constraints. Edge
selection rejects lanes whose turns fall inside node no-turn zones and
also rejects lanes whose orthogonal segments intersect non-endpoint
nodes. For mixed fan-in targets, layout now adds a shared
`preferredBendX` hint so off-row incoming edges converge on a common
merge lane when safe.

Coverage was expanded with focused routing tests for node-body crossing
avoidance, near-target lane fallback in same-row sibling scenarios,
shared preferred merge-lane convergence, and merge-hint assignment at
the layout layer.

* Refactor workflow diagram and harden deps

Workflow diagram logic had grown monolithic in
`src/components/WorkflowDiagram.tsx`, mixing React wiring with graph
construction, Dagre layout, and edge styling. It also crashed on some
historical payloads where `metadata.deps` was missing, because the graph
model read `job.metadata.deps` directly.

This refactor moves workflow diagram code into
`src/components/workflow-diagram/` and separates responsibilities across
`workflowDiagramGraphModel.ts`, `workflowDiagramLayout.ts`,
`workflowDiagramGeometry.ts`, and `workflowDiagramConstants.ts`, while
keeping edge-path routing and merge hints in dedicated modules. The
model builder now normalizes dependency reads with
`job.metadata.deps ?? []` so missing deps are treated as empty lists.

The change preserves rendering behavior and routing parity while
improving maintainability and preventing runtime failures for malformed
or historical rows. Coverage adds regressions for missing
`metadata.deps` in `WorkflowDiagram.test.tsx` and
`workflowDiagramGraphModel.test.ts`, alongside relocated routing and
merge-hint tests in the new module folder.

* Share workflow job fixture across tests

Author: bgentry

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Prevent double slash in URLs for root path prefix. Thanks [Jan Kott](https://github.com/boostvolt)! [PR #487](https://github.com/riverqueue/riverui/pull/487).
 - Serve UI HTML for wildcard or missing Accept headers and return 406 for explicit non-HTML requests. Fixes #485. [PR #493](https://github.com/riverqueue/riverui/pull/493).
 - Prevent jobs detail navigation from bouncing back to `/jobs/` on slow networks due to stale filter-sync URL updates. Fixes #495. [PR #504](https://github.com/riverqueue/riverui/pull/504).
+- Workflow detail: improve dependency edge routing to avoid turns under task cards, avoid line segments crossing node bodies, and keep fan-in edges visually converged into shared merge lanes when possible. [PR #507](https://github.com/riverqueue/riverui/pull/507).
 
 ## [v0.14.0] - 2026-01-02
 

src/components/WorkflowDetail.tsx

@@ -5,7 +5,7 @@ import RelativeTimeFormatter from "@components/RelativeTimeFormatter";
 import RetryWorkflowDialog from "@components/RetryWorkflowDialog";
 import { TaskStateIcon } from "@components/TaskStateIcon";
 import TopNavTitleOnly from "@components/TopNavTitleOnly";
-import WorkflowDiagram from "@components/WorkflowDiagram";
+import WorkflowDiagram from "@components/workflow-diagram/WorkflowDiagram";
 import { useFeatures } from "@contexts/Features.hook";
 // (Dialog is now encapsulated in RetryWorkflowDialog)
 import { ArrowPathIcon, XCircleIcon } from "@heroicons/react/24/outline";