fix(#240): add @Schema(requiredMode=REQUIRED) to both queue DTOs; add V37 indexes

All non-null DTO fields are now marked required so the generated api.ts
emits required (non-optional) types for callers. V37 migration adds
created_at/updated_at indexes on document_annotations and transcription_blocks
to avoid full table scans in the weekly stats correlated subqueries.

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

backend/src/main/java/org/raddatz/familienarchiv/dto/TranscriptionQueueItemDTO.java

@@ -1,5 +1,7 @@
 package org.raddatz.familienarchiv.dto;
 
+import io.swagger.v3.oas.annotations.media.Schema;
+
 import java.time.LocalDate;
 import java.util.UUID;
 
@@ -9,10 +11,10 @@ import java.util.UUID;
  * in the Transkription column and the percentage label in Lesefertig.
  */
 public record TranscriptionQueueItemDTO(
-        UUID id,
-        String title,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) UUID id,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String title,
         LocalDate documentDate,
-        int annotationCount,
-        int textedBlockCount,
-        int reviewedBlockCount
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) int annotationCount,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) int textedBlockCount,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) int reviewedBlockCount
 ) {}

backend/src/main/java/org/raddatz/familienarchiv/dto/TranscriptionWeeklyStatsDTO.java

@@ -1,12 +1,14 @@
 package org.raddatz.familienarchiv.dto;
 
+import io.swagger.v3.oas.annotations.media.Schema;
+
 /**
  * Weekly activity pulse for the Mission Control Strip column headers.
  * Counts documents that received new work in each pipeline stage
  * during the last 7 days.
  */
 public record TranscriptionWeeklyStatsDTO(
-        long segmentationCount,
-        long transcriptionCount,
-        long readyCount
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) long segmentationCount,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) long transcriptionCount,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) long readyCount
 ) {}

backend/src/main/resources/db/migration/V37__add_transcription_queue_indexes.sql

@@ -0,0 +1,6 @@
+-- Indexes to support the weekly stats correlated subqueries in findWeeklyStats().
+-- Without these, COUNT(DISTINCT ...) with a date range filter performs a full table scan
+-- on every dashboard load.
+CREATE INDEX IF NOT EXISTS idx_document_annotations_created_at ON document_annotations(created_at);
+CREATE INDEX IF NOT EXISTS idx_transcription_blocks_created_at  ON transcription_blocks(created_at);
+CREATE INDEX IF NOT EXISTS idx_transcription_blocks_updated_at  ON transcription_blocks(updated_at);