feat: replace webpack with esbuild (100s → 2.3s builds)

[ChakshuGautam]

Summary

• Adds esbuild as the production bundler, reducing frontend build times from ~100 seconds (webpack) to ~2.3 seconds
• build:webpack script now runs yarn build:libraries && yarn build:esbuild — the webpack config is preserved for local dev (yarn start) but production builds use esbuild
• Adds dev-build.sh for fast local iteration: rebuild + deploy to running container in ~4 seconds

Changes

File	What
esbuild.build.js	Full esbuild config: CDN externals plugin (React, ReactDOM, etc. from unpkg), SVG loader, React dedup aliases, HTML injection into public/index.html, chunk splitting
dev-build.sh	Shell script for local dev: runs esbuild + copies output to running digit-ui container
webpack.config.js	Adds resolve.alias for local core module source + React singleton (prevents "Invalid hook call" from duplicate React instances)
package.json	Adds esbuild dep, build:esbuild script, updates build:webpack to call esbuild

How it works

esbuild bundles the app into build/ with:

• CDN externals: React, ReactDOM, react-router-dom, etc. loaded from unpkg <script> tags (same pattern as existing setup)
• SVG plugin: Wraps SVG imports as React components
• React dedup: Aliases React/ReactDOM/react-query to single instances from node_modules/
• Local source override: @egovernments/digit-ui-module-core resolves to local micro-ui-internals/packages/modules/core so custom App.js/Login changes are included
• HTML injection: Injects built JS/CSS into public/index.html template

Test plan

• Run yarn build:webpack — should complete in ~3 seconds and produce build/ directory
• Run Docker build — docker build -f docker/Dockerfile . should succeed
• Verify the built app loads at /digit-ui/ with all pages functional
• Verify yarn start (webpack dev server) still works for local development

🤖 Generated with Claude Code

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