fix(network): first-wins Map lookups for colliding graph ids

[cursor]

Description

#1377 already replaced linear NetworkGraph selection scans with memoized Maps. That head still built edgeMap / nodeInstanceMap with last-wins new Map(items.map(...)), while nodeMap and the previous .find() path were first-wins. A repeated relationship id therefore opened the later edge while labels still described the first node pair.

This successor keeps constant-time lookups and makes colliding ids select the first instance. Rendered vis-network selectNode / selectEdge events are now exercised with mixed numeric and string ids instead of relying only on a source-substring scan.

Fixes the remaining review gap on #1377. Supersedes #1377 for merge. #1358 remains a narrower node-label-only slice and should not land in parallel.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

TDD boundary

The RED run of keeps the first edge instance when duplicate relationship ids collide failed on e75ce01a with last-wins detail 선택된 관계: 김지현 -> 일정 (일정 후보 1건). The production fix is e74695e5.

Exact verification commands

Run from frontend/ on the unchanged candidate head:

pnpm test -- src/components/NetworkGraph.test.tsx src/components/NetworkGraph.map-lookup.test.ts
pnpm exec eslint src/components/NetworkGraph.tsx src/components/NetworkGraph.test.tsx src/components/NetworkGraph.map-lookup.test.ts
pnpm typecheck

Local evidence on e74695e5: 432 passed, ESLint clean, tsc --noEmit clean. Hosted exact-head Application CI, security, and required central workflows remain authoritative. Queued, skipped, stale, predecessor-head, or model-only results are non-passing.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Merge boundary

Merge only if the unchanged final head satisfies every live repository + inherited organization rule, every required exact-head check is terminal-success, all addressed review threads are resolved, and a qualifying independent non-author approval exists after the last push. No self-approval or bypass. Do not merge #1377 or #1358 separately.

  

[github-actions]

PR governance metadata gate is not ready for f8317e5c9c49315e3daef5453ca4aa8c78529ad3:

• Required check metadata could not be read; see the workflow run log.

[cursor]

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[cursor]

Merged current develop to clear the DIRTY conflict in frontend/src/components/NetworkGraph.tsx.

Exact head f8317e5c keeps first-wins nodeMap.get(...) selection labels. Develop’s extra comments and the per-instance node.label read were dropped so colliding ids still describe the first node. Focused vitest: src/components/NetworkGraph.map-lookup.test.ts and src/components/NetworkGraph.test.tsx — 13 passed.

[seonghobae]

APPROVE on f8317e5. Last commit author/committer is cursoragent, not this reviewer. frontend, backend Python 3.14, coverage-evidence, images, Semgrep, CodeQL, security are green. metadata-only gate failed because required-check metadata could not be read (GitHub partial outage), not a product defect.