fix(auth): tighten API URL match, add Retry-After header, and add missing tests

- frontend/hooks.server.ts: replace request.url.includes('/api/') with
  new URL(request.url).pathname.startsWith('/api/') so a page named
  /my-api/something cannot accidentally match the API gate
- DomainException: add optional retryAfterSeconds field and a new
  tooManyRequests() factory overload that carries the value
- LoginRateLimiter: pass windowMinutes * 60 as retryAfterSeconds when
  throwing TOO_MANY_LOGIN_ATTEMPTS (RFC 6585 §4 SHOULD)
- GlobalExceptionHandler: emit Retry-After header when retryAfterSeconds
  is set on a DomainException
- RateLimitInterceptor: emit Retry-After: 60 on 429 responses (1-min
  window matches the existing MAX_REQUESTS_PER_MINUTE logic)
- LoginRateLimiterTest: assert retryAfterSeconds equals window duration
- RateLimitInterceptorTest: assert Retry-After header is set on 429
- JdbcSessionRevocationAdapterIntegrationTest: new @SpringBootTest +
  Testcontainers test verifying revokeAll deletes all spring_session rows
  and revokeOther leaves the current session intact

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

backend/src/test/java/org/raddatz/familienarchiv/auth/JdbcSessionRevocationAdapterIntegrationTest.java

@@ -0,0 +1,136 @@
+package org.raddatz.familienarchiv.auth;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.transaction.support.TransactionTemplate;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.time.Instant;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration test for {@link JdbcSessionRevocationAdapter} that verifies
+ * session rows are actually written to / removed from the {@code spring_session}
+ * table backed by a real PostgreSQL container.
+ *
+ * <p>Sessions are inserted via raw JDBC to avoid the module-access restriction on
+ * {@code JdbcIndexedSessionRepository.JdbcSession}. The {@link SessionRevocationPort}
+ * bean injected here is the real {@link JdbcSessionRevocationAdapter} wired by Spring.
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+class JdbcSessionRevocationAdapterIntegrationTest {
+
+    @MockitoBean S3Client s3Client;
+
+    @Autowired SessionRevocationPort adapter;
+    @Autowired JdbcTemplate jdbcTemplate;
+    @Autowired TransactionTemplate transactionTemplate;
+
+    private static final String PRINCIPAL = "revocation-it@test.de";
+
+    @BeforeEach
+    void clearSessions() {
+        // spring_session_attributes cascades on delete
+        transactionTemplate.execute(status -> {
+            jdbcTemplate.update("DELETE FROM spring_session");
+            return null;
+        });
+    }
+
+    // ── helper ─────────────────────────────────────────────────────────────────
+
+    /**
+     * Inserts a minimal {@code spring_session} row attributed to {@value #PRINCIPAL}
+     * and returns its opaque primary-key ID (the value the repository uses as the
+     * session identifier, not the {@code SESSION_ID} column which holds the public token).
+     *
+     * <p>Column layout mirrors the Flyway-managed schema shipped with the app:
+     * PRIMARY_ID, SESSION_ID, CREATION_TIME, LAST_ACCESS_TIME, MAX_INACTIVE_INTERVAL,
+     * EXPIRY_TIME, PRINCIPAL_NAME.
+     */
+    /**
+     * Inserts a persisted session row for {@value #PRINCIPAL} and returns the
+     * {@code SESSION_ID} column value — this is the opaque identifier that
+     * {@link JdbcIndexedSessionRepository} uses as the session's public key
+     * (returned by {@code JdbcSession.getId()} and expected by
+     * {@link JdbcIndexedSessionRepository#deleteById}).
+     *
+     * <p>The inserts run inside a {@link TransactionTemplate} so the rows are
+     * committed before {@code findByPrincipalName} opens its own transaction and
+     * can see the data via Read Committed isolation.
+     */
+    private String insertSession() {
+        String primaryId = UUID.randomUUID().toString();
+        // SESSION_ID is the value used by JdbcSession.getId() and findByPrincipalName map keys.
+        String sessionId  = UUID.randomUUID().toString();
+        long   now        = Instant.now().toEpochMilli();
+        long   expiry     = now + 8L * 3600 * 1000; // 8-hour TTL
+        transactionTemplate.execute(status -> {
+            jdbcTemplate.update("""
+                    INSERT INTO spring_session
+                        (PRIMARY_ID, SESSION_ID, CREATION_TIME, LAST_ACCESS_TIME,
+                         MAX_INACTIVE_INTERVAL, EXPIRY_TIME, PRINCIPAL_NAME)
+                    VALUES (?, ?, ?, ?, ?, ?, ?)
+                    """,
+                    primaryId, sessionId, now, now, 28800, expiry, PRINCIPAL);
+            // Spring Session's listSessionsByPrincipalName query joins spring_session_attributes;
+            // insert a minimal attribute row so the session appears in the result set.
+            jdbcTemplate.update("""
+                    INSERT INTO spring_session_attributes
+                        (SESSION_PRIMARY_ID, ATTRIBUTE_NAME, ATTRIBUTE_BYTES)
+                    VALUES (?, ?, ?)
+                    """,
+                    primaryId, "test_attr", new byte[]{0});
+            return null;
+        });
+        return sessionId;  // the public key used by JdbcSession.getId() and deleteById()
+    }
+
+    // ── tests ──────────────────────────────────────────────────────────────────
+
+    @Test
+    void revokeAllSessions_removes_every_row_from_spring_session_table() {
+        insertSession();
+        insertSession();
+
+        int count = adapter.revokeAllSessions(PRINCIPAL);
+
+        assertThat(count).isEqualTo(2);
+        assertThat(jdbcTemplate.queryForObject(
+                "SELECT COUNT(*) FROM spring_session WHERE PRINCIPAL_NAME = ?",
+                Long.class, PRINCIPAL))
+            .isZero();
+    }
+
+    @Test
+    void revokeOtherSessions_deletes_non_current_rows_and_keeps_current_session() {
+        String keepId = insertSession();
+        insertSession();
+        insertSession();
+
+        int count = adapter.revokeOtherSessions(keepId, PRINCIPAL);
+
+        assertThat(count).isEqualTo(2);
+        // The current session row must still be present (keyed by SESSION_ID)
+        assertThat(jdbcTemplate.queryForObject(
+                "SELECT COUNT(*) FROM spring_session WHERE SESSION_ID = ?",
+                Long.class, keepId))
+            .isEqualTo(1L);
+        // The total for this principal is now exactly 1
+        assertThat(jdbcTemplate.queryForObject(
+                "SELECT COUNT(*) FROM spring_session WHERE PRINCIPAL_NAME = ?",
+                Long.class, PRINCIPAL))
+            .isEqualTo(1L);
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/auth/LoginRateLimiterTest.java

@@ -42,6 +42,18 @@ class LoginRateLimiterTest {
                 .isEqualTo(ErrorCode.TOO_MANY_LOGIN_ATTEMPTS));
     }
 
+    @Test
+    void blocked_attempt_carries_retry_after_seconds_equal_to_window_duration() {
+        for (int i = 0; i < 10; i++) {
+            rateLimiter.checkAndConsume("1.2.3.4", "user@example.com");
+        }
+
+        assertThatThrownBy(() -> rateLimiter.checkAndConsume("1.2.3.4", "user@example.com"))
+            .isInstanceOf(DomainException.class)
+            .satisfies(ex -> assertThat(((DomainException) ex).getRetryAfterSeconds())
+                .isEqualTo(15 * 60L));  // windowMinutes=15 → 900 seconds
+    }
+
     @Test
     void success_after_10_failures_resets_ip_email_bucket() {
         for (int i = 0; i < 10; i++) {

backend/src/test/java/org/raddatz/familienarchiv/config/RateLimitInterceptorTest.java

@@ -45,6 +45,15 @@ class RateLimitInterceptorTest {
         verify(response).setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
     }
 
+    @Test
+    void blocked_response_includes_retry_after_header() throws Exception {
+        for (int i = 0; i < 10; i++) {
+            interceptor.preHandle(request, response, null);
+        }
+        interceptor.preHandle(request, response, null);
+        verify(response).setHeader("Retry-After", "60");
+    }
+
     @Test
     void different_ips_have_independent_limits() throws Exception {
         HttpServletRequest other = mock(HttpServletRequest.class);