refactor: centralise duplicate frontend helpers

[NotYuSheng]

Summary

• Extracts shared network filter/label utilities (applyNetworkFilters, buildActiveFilterLabels, edgeMatchesLegendKey, toggleSet) so NetworkDiagramPage, ComparePage, and AnalysisPage all use the same logic
• Removes inline copies of formatBytes, parseDateTime, confidenceLevel, buildDeviceSignals scattered across pages and popup components
• Adds useClickOutside utility hook to replace identical useEffect patterns in both classification popups

Changes

Removed duplicate	Was in	Now lives in
parseDateTime	timelineService.ts	utils/dateUtils.ts
formatBytes	NetworkDiagramPage, ComparePage	utils/formatters
toggleSet	NetworkDiagramPage, ComparePage	features/network/constants.ts
edgeMatchesLegendKey	ComparePage	networkService.ts
Edge filter logic	ComparePage inline useMemo	networkService.applyNetworkFilters()
confidenceLevel	Both classification popups	utils/deviceType.ts
buildDeviceSignals	Both classification popups	utils/deviceType.ts
Click-outside useEffect	Both classification popups	utils/useClickOutside.ts (new)

Net: −235 lines added, +95 lines → −140 lines of duplicated code.

Test plan

• Network Diagram page: filters (protocol, node type, IP, port, risks, app, L7, category, etc.) all still work
• Compare page: same filters work; per-file source toggle still hides/shows edges
• Report download: active filter labels and node-limit note appear correctly in generated PDF
• Both classification popups close on outside click
• Confidence bar and device signals display correctly in both popups
• Timeline page loads without errors

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request centralizes and refactors network filtering logic, device classification utilities, and common UI behaviors into shared services and hooks, significantly reducing code duplication across the Analysis, Compare, and Network Diagram pages. Feedback was provided regarding a performance bottleneck in the IP filtering logic within networkService.ts, where replacing a nested loop with a Set-based lookup would improve efficiency as the graph size increases.

[NotYuSheng]

/gemini review

[gemini-code-assist]

Code Review

This pull request centralizes network filtering logic, device classification utilities, and UI components across the frontend, including the introduction of a useClickOutside hook and consolidated filtering functions in networkService.ts. Backend updates improve exception handling for LLM-related errors. Feedback identifies a performance bottleneck in the centralized filtering logic that could be optimized from $O(N \cdot E)$ to $O(N + E)$ using a Set. Additionally, the reviewer recommends fully adopting the new filtering function in NetworkDiagramPage and refining the error detection logic in StoryPage.tsx to avoid overly broad string matching.