feat: add Pydantic response models and OpenAPI docs to analytics service

[Sundriveauto]

Summary

Adds typed Pydantic schemas and full OpenAPI documentation to the FastAPI analytics service.

Changes

• schemas.py — all request/response models with field descriptions and examples
• main.py — app-level description documenting auth requirements; explicit /docs and /redoc URLs
• routes/analytics.py — response_model, summary, description + HTTPBearer security on all three endpoints
• routes/batch.py — BatchVerifyRequest (max 100 wallets), BatchVerifyResponse, 400 error documented, auth note in description

Acceptance Criteria

• /docs (Swagger UI) and /redoc available
• All endpoints have Pydantic response models with field descriptions
• Batch verify documents input format, size limits (max 100), and error responses
• Authentication requirements documented per endpoint (Bearer JWT on analytics, public on batch/health)

Tested

Verified via app.openapi() — all 5 paths present, analytics endpoints show security=True, batch shows responses=['200','400','422'].