feat: integrate Codacy for automated code quality analysis

[MatiasOS]

Description

Integrate Codacy into the OpenScan CI pipeline to get automated code quality reviews, duplication detection, and complexity analysis on every PR.

Part of the Quality Tooling Rollout (#369).

Tasks

• Set up Codacy project for the OpenScan repo
• Configure with project-specific rules (TypeScript, React, Bun)
• Connect Codacy to GitHub for PR annotations and status checks
• Add Codacy badge to README
• Tune rule set — start with recommended defaults, then adjust based on team feedback

Motivation

Biome handles formatting and linting locally, but Codacy adds:

• Duplication and complexity metrics
• Historical quality trends over time
• Cross-PR comparison and diff annotations

Notes

• Should not block CI initially — informational only until rules are tuned.