feat(kyc): integrate darvest-common 0.0.3 and validate KYC APIs (MVP 1–3)

## Summary

This MR integrates the darvest-investor-profile-kyc-service with darvest-common 0.0.3-RELEASE, aligns service configuration with the shared KYC contracts, and documents verified API behaviour for MVP 1 through MVP 3.

## Scope

• Dependency: darvest-common upgraded/locked to 0.0.3-RELEASE
• Configuration: application settings aligned with the KYC module expectations from the common library
• Documentation: CHANGELOG.md updated with feature scope and manual verification matrix

## Functional coverage

Area	Capabilities
MVP 1 — KYC request	Create dossier, fetch by userId, update status; admin verification flows
MVP 2–3 — Documents	Upload metadata, list by dossier, document status updates, admin reviewer actions

## Verification

• Manual API testing performed in Postman (end-to-end against running service)
• Happy paths and negative cases exercised (invalid transitions, duplicate request, review rules, REJECTED without reason, upload edge cases including fileSize = 0)
• Outcome: responses and behaviour match expected rules for all listed scenarios

## Checklist

• Configuration reviewed for target environments (dev/stage)
• No breaking changes for consumers unless already coordinated
• Changelog entry reflects this release scope

Notes

Automated tests for the full matrix are out of scope for this MR; validation is manual (Postman) for this iteration.