fix: resolve Docker pnpm corepack signature verification issue for M1/Linux

[rishavr920]

Problem

Docker build fails on M1/Linux with pnpm 10.28.1 corepack signature error:
Internal Error: Cannot find matching keyid

Root Cause

pnpm@10.28.1 has signature verification issues with corepack

Solution

• Downgrade pnpm from 10.28.1 to 9.12.3 (stable version)
• Replace corepack prepare with npm install -g
• Updated both Dockerfile and docker-compose.yaml

Files Changed

• Dockerfile
• docker-compose.yaml

Testing

• Docker build successful on M1 Mac ✅
• Development server running correctly ✅
• Hot-reload working ✅

[bobbyonmagic]

Thank you!