Add Linting Infrastructure and CI/CD Pipeline (and Prettier reformatting)

[bakiberkay]

This PR implements the linting infrastructure and CI/CD pipeline requirements, addressing issues #10 and #7

1. Linting Infrastructure

• Added Husky 9.1.7 + lint-staged for pre-commit hooks
• Added Prettier 3.8.1 with .prettierrc configuration file
• Integrated eslint-config-prettier to prevent ESLint/Prettier rule conflicts
• Added Solhint 6.0.3 for Solidity linting with .solhint.json configuration. NOTE: Solhint uses relaxed rules currently, as the contracts require major reformatting to align with default configuration.

2. CI/CD Pipeline

• Structured workflow to lint -> test -> build with contract deployment step to follow
• Added ci.yml for the flow
• Added frontend build step (npm run build) to verify build succeeds
• Updated to Node.js 22.12.0 in the Dockerfile to match across all environments.

3. Documentation

• Created CI_CD.md with pipeline documentation and troubleshooting, and also future work
• Updated BUILD.md with Development Workflow section explaining pre-commit hooks
• Updated README.md with root npm install step for Husky setup

4. Commit Structure

• Commit 1: Infrastructure and configuration files; this is the main commit, including all the relevant files
• Commit 2: Prettier formatting changes only. Prettier formating caused ALL existing .ts files to get reformatted. However, there are not functional changes, not necessary to review if not for testing purposes