fix(analytic): resolve analytics lint issues, add route generics, and add tests

[Harxhit]

Summary

Improves analytics route reliability and maintainability by resolving lint issues, introducing stronger Fastify route typing using route generics, and adding automated test coverage for analytics endpoints. These changes improve TypeScript safety and ensure analytics functionality is validated through tests.

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Type of Change

• Bug fix
• Refactor (no functional change)
• Tests only
• New feature
• UI / Design change
• Documentation
• Infrastructure / DevOps
• Security

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What Changed

• Fixed lint issues in analytics.ts, including unused variables and ESLint unbound-method warnings for authentication handlers.
• Added Fastify route generics for /views to improve query typing and TypeScript safety.
• Added automated tests for analytics endpoints (/overview and /views) using mocked Prisma and Fastify inject-based testing.
• Improved route typing consistency while preserving existing analytics logic and API behavior.

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How to Test

1. Run lint checks:

pnpm eslint src/analytic.ts

2. Run test:

pnpm test analytics.test.ts