Remove duplicated Spring/Kotlin/Testing guidance from AGENTS.md files; replace with references to docs/

Co-authored-by: afranken <763000+afranken@users.noreply.github.com>

Author: Copilot

AGENTS.md

@@ -29,37 +29,21 @@ docker/              # Docker image build
 
 ## DO / DON'T
 
+> For Kotlin idioms and naming conventions, see **[docs/KOTLIN.md](docs/KOTLIN.md)**.
+> For Spring Boot patterns and testing setup, see **[docs/SPRING.md](docs/SPRING.md)**.
+> For testing conventions and commands, see **[docs/TESTING.md](docs/TESTING.md)**.
+
 ### DO
-- Use **constructor injection** for all Spring beans (in production code)
 - Use **data classes** for DTOs with Jackson XML annotations
-- Use **Kotlin stdlib** and built-in language features over third-party utilities
 - Use **AWS SDK v2** for all new integration tests
 - Use **JUnit 5** for all new tests
-- Use **`@SpringBootTest`** with **`@MockitoBean`** for unit tests — this is the project's standard mocking approach
-- Use **expression bodies** for simple functions
-- Use **null safety** (`?`, `?.`, `?:`) instead of null checks
-- **Name the `it` parameter** in nested lambdas, loops, and scope functions to avoid shadowing: `.map { part -> ... }` instead of `.map { it.name }`
-- Match **AWS S3 API naming exactly** in Jackson XML annotations (`localName = "..."`)
-- Keep tests **independent** — each test creates its own resources (UUID bucket names)
-- Use **backtick test names** with descriptive sentences: `` fun `should create bucket successfully`() ``
-- Mark test classes as **`internal`**: `internal class ObjectServiceTest`
-- **Refactor** legacy `testSomething` camelCase names to backtick style when touching existing tests
 - **Update the copyright year** in the file's license header to the current year whenever you modify an existing file
 - Validate XML serialization against [AWS S3 API documentation](https://docs.aws.amazon.com/AmazonS3/latest/API/Welcome.html)
 
 ### DON'T
-- DON'T use `@Autowired` or field injection in production code — always use constructor injection
-- DON'T use `var` for public API properties — prefer `val` (immutability)
 - DON'T use AWS SDK v1 — it has been removed in 5.x
 - DON'T use JUnit 4 — it has been removed in 5.x
-- DON'T use `@ExtendWith(MockitoExtension::class)` or `@Mock` / `@InjectMocks` — use `@SpringBootTest` with `@MockitoBean` instead
-- DON'T add Apache Commons dependencies — use Kotlin stdlib equivalents
-- DON'T put business logic in controllers — controllers only map HTTP, delegate to services
-- DON'T return raw strings from controllers — use typed DTOs for XML/JSON responses
 - DON'T declare dependency versions in sub-module POMs — all versions are managed in root `pom.xml`
-- DON'T share mutable state between tests — each test must be self-contained
-- DON'T hardcode bucket names in tests — use `UUID.randomUUID()` for uniqueness
-- DON'T use legacy `testSomething` camelCase naming for new tests — use backtick names instead
 - DON'T update copyright years in files you haven't modified — copyright is only bumped when a file is actually changed
 
 ## Code Style
@@ -105,7 +89,7 @@ Environment variables (prefix: `COM_ADOBE_TESTING_S3MOCK_STORE_`):
 
 Services throw `S3Exception` constants (`NO_SUCH_BUCKET`, `NO_SUCH_KEY`, `INVALID_BUCKET_NAME`, etc.).
 Spring exception handlers convert them to XML `ErrorResponse` with the correct HTTP status.
-See `server/AGENTS.md` for details.
+See **[docs/SPRING.md](docs/SPRING.md)** for exception handling patterns and `server/AGENTS.md` for the concrete handler classes.
 
 ## Testing
 

docs/TESTING.md

@@ -67,8 +67,6 @@ Access `serviceEndpoint`, `serviceEndpointHttp`, and `serviceEndpointHttps` from
 
 See **[docs/KOTLIN.md](KOTLIN.md)** for Kotlin naming conventions (backtick test names, `internal` visibility, naming patterns).
 
-- **Naming**: Backtick names with descriptive sentences — `` fun `should create bucket successfully`() ``
-- **Visibility**: Mark test classes `internal`
 - **Pattern**: Arrange-Act-Assert
 - **Assertions**: AssertJ (`assertThat(...)`) — use specific matchers, not just `isNotNull()`
 - **Error cases**: Use AssertJ, not JUnit `assertThrows`:
@@ -78,7 +76,6 @@ See **[docs/KOTLIN.md](KOTLIN.md)** for Kotlin naming conventions (backtick test
     .hasMessageContaining("Status Code: 409")
   ```
 - **Independence**: Each test creates its own resources — no shared state, UUID-based bucket names
-- **Legacy names**: Refactor `testSomething` camelCase names to backtick style when touching existing tests
 
 ## Running Tests
 

server/AGENTS.md

@@ -36,14 +36,15 @@ server/src/main/kotlin/com/adobe/testing/s3mock/
 
 1. **DTO** (`dto/`): Data classes with Jackson XML annotations (`@JacksonXmlRootElement`, `@JacksonXmlProperty`, `@JacksonXmlElementWrapper(useWrapping = false)`). Verify element names against [AWS S3 API docs](https://docs.aws.amazon.com/AmazonS3/latest/API/Welcome.html).
 2. **Store** (`store/`): Filesystem path resolution, binary storage, metadata JSON. Key classes: `BucketStore`, `ObjectStore`, `BucketMetadata`, `S3ObjectMetadata`.
-3. **Service** (`service/`): Validation, store coordination. Throw **`S3Exception` constants** (e.g., `S3Exception.NO_SUCH_BUCKET`) — don't create new exception classes.
+3. **Service** (`service/`): Validation, store coordination. Throw **`S3Exception` constants** (e.g., `S3Exception.NO_SUCH_BUCKET`) — see **[docs/SPRING.md](../docs/SPRING.md)** for exception handling rules.
 4. **Controller** (`controller/`): HTTP mapping only — delegate all logic to services. Controllers never catch exceptions.
 
 ## Error Handling
 
 - `S3MockExceptionHandler` converts `S3Exception` → XML `ErrorResponse` with the correct HTTP status
 - `IllegalStateExceptionHandler` converts unexpected errors → `500 InternalError`
-- Add new error types as constants in `S3Exception` — DON'T create new exception classes
+
+See **[docs/SPRING.md](../docs/SPRING.md)** for exception handling patterns and rules.
 
 ## Testing