Spring Security 7.1 JWT authentication on Spring Boot 4.1

Runnable companion for https://ankurm.com/spring-security-7-1-jwt-authentication-guide/

- login -> token issue -> OncePerRequestFilter -> SecurityContext, end to end
- HS256 and RS256 variants (RS256 publishes a real JWKS endpoint)
- the same API secured by the built-in oauth2ResourceServer().jwt(), for comparison
- 11 documentation chapters under docs/, interlinked with the code
- docs/output/ is real captured output, regenerated by scripts/run-all.sh
- 13 passing tests pinning the 401-vs-403 contract and the CSRF failure

Verified against Spring Boot 4.1.1, Spring Security 7.1.1, JDK 25.0.4.1.

src/main/java/com/ankurm/jwtauth/auth/AuthDtos.java

@@ -0,0 +1,17 @@
+package com.ankurm.jwtauth.auth;
+
+import jakarta.validation.constraints.NotBlank;
+
+public final class AuthDtos {
+
+    private AuthDtos() { }
+
+    public record LoginRequest(@NotBlank String username, @NotBlank String password) { }
+
+    public record RefreshRequest(@NotBlank String refreshToken) { }
+
+    public record TokenResponse(String accessToken,
+                                String refreshToken,
+                                String tokenType,
+                                long expiresIn) { }
+}