spring-batch

# Spring Batch Spring Boot 4.x ships **Spring Batch 6**. The API changed significantly from 5.x (and drastically from 4.x) — most online examples are wrong. The rules that break the most agent-generated code: 1. **Do NOT add `@EnableBatchProcessing`.** Boot auto-configures the `JobRepository`, `JobOperator`, and transaction manager. Adding `@EnableBatchProcessing` **disables** that auto-configuration and you lose all the wired beans. 2. **Metadata is in-memory by default.** Batch 6's `JobRepository` is *resourceless* — nothing is persisted. Restartability and the `BATCH_*` audit tables require the `spring-boot-starter-batch-jdbc` starter (plain `spring-boot-starter-batch` = no restart after a crash). 3. **`JobLauncher` and `JobExplorer` are consolidated into `JobOperator`** (which extends both). Inject `JobOperator` and call `start(job, params)`. 4. **`JobBuilderFactory`/`StepBuilderFactory` are long gone**, and `chunk(500, txManager)` is the old Batch 5 style — Batch 6 takes the size alone, with an optional `.transactionManager(...)`. ## Dependencies ```xml <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-batch-jdbc</artifactId> <!-- persistent BATCH_* metadata --> </dependency> <!-- spring-boot-starter-batch alone = resourceless in-memory repository: fine for run-and-forget jobs, but no restart-on-failure, no audit trail --> ``` ## Job & Step (Spring Batch 6 API) ```java @Configuration @Required...