feat(flow): complete Dify node design system

[1012839419a-alt]

Summary

• Replaces the workflow-node visual monolith with composable node primitives, fixed 240px-width geometry, status/package-state styling, Lucide icon lookup, and typed IN/OUT interface rows.
• Shares workflow-node geometry between rendering, pre-measure placement, collision detection, and layout; canvas density now uses one low/mid/high contract.
• Moves image-workspace actions and map/runtime/relationship detail from the canvas node into the Inspector, preserving the existing Image Studio query parameters.
• Adds node-design regression assertions and a Canvas Playwright scenario covering geometry, handles, density, keyboard port menus, Inspector image actions, and light/dark screenshots.

Deliberate non-goals

• No change to workflow semantics, canonical/runtime data, port direction, or graph layout direction.
• No app-wide component-library replacement or redesign of other node types.
• No inline image authoring, asset gallery, full prompts, debug values, or mini-networks inside workflow nodes; those details remain in the Inspector/workspace.

Verification

Recorded in the implementation spec on 2026-08-28:

• npm --prefix frontend run lint — passed with 0 errors (2 existing warnings).
• npm --prefix frontend run build — passed, including TypeScript and SSR/static generation.
• npm --prefix frontend run check:workflow — passed; npm --prefix frontend run check:workflow-image — 9/9 passed.
• npm --prefix frontend run test:smoke -- workflow-node-design.spec.mjs — passed against a fresh frontend dev server at 127.0.0.1:3001.
• Manual Canvas check covered light/dark surfaces, fixed 240px nodes, visible port metadata, Lucide icons, and port anchors.

Review order

1. frontend/lib/flow/node-geometry.ts, then its consumers in collision, layout, store, and to-react-flow.
2. frontend/components/flow/nodes/workflow-node.tsx for contract resolution and node composition.
3. frontend/components/flow/nodes/workflow-node-primitives.tsx for handle semantics, keyboard menu access, and remeasurement.
4. frontend/components/flow/workflow-canvas-surface.tsx and frontend/app/flow-canvas.css for density and composable visual states.
5. frontend/components/flow/inspector.tsx, then icons and regression coverage.

Stack

This PR is stacked directly on PR 2233admin#80: its parent is 7c2d19790890da5835292b82f1e1607766d6748b, and this change is ef80e8f3a311ec46ed6f54544e74156c4417d834. Review the delta against that parent; land or rebase this PR after 2233admin#80.