ATLAS-5346: Atlas React UI: Reduce React UI build time and bundle size through Vite optimization and lazy route loading.

[pawarprasad123]

What changes were proposed in this pull request?

Optimizes Atlas React UI (dashboard/) production build performance by ~50%, improves bundle splitting with lazy-loaded routes, and streamlines the Maven/npm build pipeline.

• npm run build wall time: 26.2s → ~12s (~13s / ~50% faster)
• Router chunk: ~837 KB → ~506 KB
• 31 files changed: ~2,742 insertions, ~3,599 deletions

Problem

The React UI build was slow because:

1. Default build ran lineage prebuild (~11.7s) + full tsc (~7.2s) before Vite on every run
2. Heavy views (Statistics, Entity Detail tabs, Administrator) were eagerly bundled
3. Maven copied unnecessary artifacts and re-downloaded Node toolchain on each build

Solution

Build pipeline

• Default npm run build is now vite build only
• Typecheck separated: npm run typecheck / npm run build:check
• Lineage build separated: npm run build:lineage / npm run build:legacy
• Maven builds from dashboard/ module root with persistent .frontend-toolchain/ and npm cache
• Added .npmrc for faster installs

Vite optimization (vite.config.ts)

• Manual chunks: react, mui, redux, router, d3, utils
• reportCompressedSize: false for faster builds
• Increased chunk size warning limit

Lazy loading

• Layout.tsx → lazy Statistics
• EntityDetailPage.tsx → lazy detail tabs (Properties, Schema, Lineage, etc.)
• AdministratorLayout.tsx → lazy admin sub-views

Code cleanup

• Removed unused Masonry demo components and standalone LineageLayout from main bundle
• Refactored Statistics: EntityStatsChart.tsx, statsUtils.tsx

Tooling

• ESLint 10 flat config (eslint.config.js replaces .eslintrc.cjs)
• Upgraded Vite 6.4.3, @vitejs/plugin-react-swc 4.3.1
• tsconfig.build.json excludes tests from production typecheck
• Platform-specific optional deps for Rollup/esbuild/SWC
• Updated npm overrides for transitive security pins

Build time comparison

Metric	Before	After	Savings
npm run build total	26.2 s	~12 s	~50%
prebuild (lineage webpack)	~11.7 s	Removed
tsc before Vite	~7.2 s	Removed (separate script)
Vite bundling	~10.7 s	~11.4 s

Files changed

Build/config: package.json, package-lock.json, vite.config.ts, tsconfig.json, tsconfig.build.json, .npmrc, .gitignore, eslint.config.js, dashboard/pom.xml, pom.xml
Scripts: ensure-lineage-build.mjs, ensure-native-deps.mjs
Views: Layout.tsx, EntityDetailPage.tsx, AdministratorLayout.tsx, Statistics refactor + tests
Removed: Masonry demo, standalone LineageLayout (lineage still via Entity Detail tab)

How was this patch tested?

Manual tested

• npm run lint — 0 errors (167 warnings, under limit)
• npm run typecheck — pass
• npm run build — pass (~11.4s)
• Unit tests — Layout, EntityDetailPage, AdministratorLayout, EntityStats, Statistics
• Manual smoke: Entity Detail tabs, Statistics modal, Administrator views, Dashboard charts
• Maven build: mvn clean install -pl dashboard -am