perf: Optimize dev container startup using anonymous volume for node_modules

[KinshukSS2]

Summary

this PR removes runtime dependency installation from dev container startup and replaces it with a persistent container-side dependency strategy.

What Changed

• Updated docker-compose_dev.yml to run npm run dev directly.
• Added anonymous volume mount for /home/node/app/node_modules.
• Updated ui/Dockerfile.dev to install dependencies during image build using npm ci.
• Updated README.md dev command references to match the compose file used by this change.

Why This Is Better

• Eliminates repeated npm install on each startup.
• Preserves hot-reload workflow through bind-mounted source code.
• Prevents host mount from masking container dependencies.
• Produces faster and more reliable restart cycles.

Validation

• Ran:

docker compose -f docker-compose_dev.yml up --build -d

• Verified container starts successfully and Next.js launches with npm run dev.
• Verified no sh: next: not found error.
• Restarted services and confirmed faster startup behavior without runtime install.

fixes #21