Add slot dimming

[benceruleanlu]

Summary

Add slot dimming by precomputing compatible targets during link drag start, improving clarity and responsiveness when connecting links.

Changes

• What: Centralize compatibility precompute on pointer down to dim incompatible slots across the canvas.
• What: Derive target side from the source slot type; remove overly defensive try/catch and optional chaining.
• What: Iterate LayoutStore slot keys; clear then set compatibility per key for simplicity.
• What: Remove redundant numeric coercions and double-negation; rely on existing types.
• Breaking: None
• Dependencies: None

Review Focus

• Validate dimming correctness for both input→output and output→input drags.
• Check performance on large graphs (single pass on start; no per-frame cost).
• Ensure no regressions with reroute snapping and node-surface candidates.

Screenshots (if applicable)

N/A

┆Issue is synchronized with this Notion page by Unito

[github-actions]

🎭 Playwright Test Results

❌ Some tests failed

⏰ Completed at: 10/06/2025, 07:13:37 PM UTC

📈 Summary

• Total Tests: 480
• Passed: 436 ✅
• Failed: 8 ❌
• Flaky: 6 ⚠️
• Skipped: 30 ⏭️

📊 Test Reports by Browser

• ✅ chromium: View Report • ✅ 427 / ❌ 8 / ⚠️ 6 / ⏭️ 30
• ✅ chromium-2x: View Report • ✅ 2 / ❌ 0 / ⚠️ 0 / ⏭️ 0
• ✅ chromium-0.5x: View Report • ✅ 1 / ❌ 0 / ⚠️ 0 / ⏭️ 0
• ✅ mobile-chrome: View Report • ✅ 6 / ❌ 0 / ⚠️ 0 / ⏭️ 0

---

🎉 Click on the links above to view detailed test results for each browser configuration.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting

• @codex fix this CI failure
• @codex address that feedback

[benceruleanlu]

some tests failed because they are failing generally in main (?)

other tests failed because some tests relied on middrag snapshots which need to be updated