fix(web): pin actor nodes to leftmost layer

[naorsabag]

Summary

• ELK could place actor nodes (the human/external initiator) at any layer that minimized total edge length, sometimes pushing user / browser inward when it also appeared as a final response target.
• Added elk.layered.layering.layerConstraint=FIRST for type: actor nodes so the actor always anchors the leftmost column.
• New test in __tests__/flow-layout.test.ts asserts that user lands at min(x) across the order-flow example layout.

Test plan

• npm test in packages/web (41/41 passing — new test included)
• Visually verify npx openhop@beta demo after merge: browser on far left of the auth flow

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Fixed flow layout behavior to ensure actor-typed nodes are correctly positioned at the leftmost layer in flow diagrams, even when they appear as edge targets. Improved per-node layout options computation for more accurate positioning.

• Tests

  • Added test validation for flow layout behavior to ensure consistent positioning of actor nodes.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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Review profile: CHILL

Plan: Pro Plus

Run ID: 7c742db4-97df-42ea-8f1e-0c0cbec2e60f

📥 Commits

Reviewing files that changed from the base of the PR and between 2cb0644 and b66c254.

📒 Files selected for processing (2)

• packages/web/__tests__/flow-layout.test.ts
• packages/web/src/lib/flow-layout.ts

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Walkthrough

This PR modifies ELK graph layout computation to pin actor-typed nodes to the leftmost layer by conditionally adding layer constraints. It refactors per-node layout options configuration and adds a test verifying actor nodes remain at the minimum x-coordinate.

Changes

Actor Node Layer Pinning

Layer / File(s)	Summary
ELK Layout Configuration packages/web/src/lib/flow-layout.ts	buildElkGraph now conditionally applies elk.layered.layering.layerConstraint: 'FIRST' to actor-typed nodes. portConstraints: 'FIXED_SIDE' is added only when portAssignments exist. The returned node structure conditionally spreads both layoutOptions and ports.
Layout Verification Test packages/web/__tests__/flow-layout.test.ts	New test case verifies computeElkLayout pins the user actor node to the leftmost layer by asserting its x position equals the global minimum x coordinate.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: pinning actor nodes to the leftmost layer in ELK layout, which matches the core implementation in flow-layout.ts and is validated by the new test.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/actor-leftmost-layer

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