Task 5: TokenService + unit tests (7/7 pass)

- ITokenService: GenerateAccessToken / GenerateRefreshToken / HashToken
- TokenService: JWT (HS256, 15-min), 64-byte CSPRNG refresh, SHA-256 hex hash
  - Role claims use short JWT name role (v7.x JsonWebTokenHandler compatible)
- TokenServiceTests: 7 xUnit tests, payload decoded via Base64Url+System.Text.Json
  to avoid Microsoft.IdentityModel 7.1.2/7.5.2 version-mismatch issues

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

API/ROLAC.API.Tests/ROLAC.API.Tests.csproj

@@ -0,0 +1,31 @@
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