docs: ensure concise documentation for customers, developers, skills and agents

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

Author: Copilot

.claude/skills/document/SKILL.md

@@ -15,6 +15,8 @@ Read `AGENTS.md` (root + relevant module) before making changes.
 | `CHANGELOG.md` | End users | Version history, breaking changes |
 | `docs/TESTING.md` | Contributors / AI agents | Testing strategy, base classes, patterns, commands |
 | `docs/KOTLIN.md` | Contributors / AI agents | Kotlin idioms, naming conventions, anti-patterns, KDoc |
+| `docs/SPRING.md` | Contributors / AI agents | Spring Boot patterns, DI, controllers, exception handling |
+| `docs/JAVA.md` | Contributors / AI agents | Java idioms, naming conventions, anti-patterns, Javadoc |
 | `AGENTS.md` (root + modules) | AI agents | Architecture, conventions, guardrails |
 | `.github/CONTRIBUTING.md` | Contributors | Dev setup, code reviews |
 
@@ -26,6 +28,10 @@ Read `AGENTS.md` (root + relevant module) before making changes.
 
 **Architecture change**: relevant module's `AGENTS.md`, root `AGENTS.md` if cross-cutting, `CHANGELOG.md`.
 
+**Spring Boot pattern change**: `docs/SPRING.md`, `server/AGENTS.md` if the change affects how controllers/services/stores are structured.
+
+**Kotlin/Java style change**: `docs/KOTLIN.md` or `docs/JAVA.md`, root `AGENTS.md` DO/DON'T section if it introduces a new guardrail.
+
 ## CHANGELOG Format
 
 Follow existing pattern: group under current version heading, clear user-facing language, note breaking changes, reference issues/PRs.

AGENTS.md

@@ -78,12 +78,14 @@ Filesystem layout:
 
 ## Configuration
 
-Environment variables (prefix: `COM_ADOBE_TESTING_S3MOCK_STORE_`):
-- `ROOT` - storage directory
-- `RETAIN_FILES_ON_EXIT` - keep files after shutdown
-- `REGION` - AWS region (default: us-east-1)
-- `INITIAL_BUCKETS` - comma-separated bucket names
-- `VALID_KMS_KEYS` - valid KMS ARNs
+Environment variables:
+- `COM_ADOBE_TESTING_S3MOCK_STORE_ROOT` - storage directory
+- `COM_ADOBE_TESTING_S3MOCK_STORE_RETAIN_FILES_ON_EXIT` - keep files after shutdown (default: false)
+- `COM_ADOBE_TESTING_S3MOCK_STORE_REGION` - AWS region (default: us-east-1)
+- `COM_ADOBE_TESTING_S3MOCK_STORE_INITIAL_BUCKETS` - comma-separated bucket names
+- `COM_ADOBE_TESTING_S3MOCK_STORE_VALID_KMS_KEYS` - valid KMS ARNs
+- `COM_ADOBE_TESTING_S3MOCK_CONTROLLER_CONTEXT_PATH` - base context path for all endpoints (default: "")
+- `debug` / `trace` - Spring Boot log levels
 
 ## Error Handling
 
@@ -100,6 +102,7 @@ See **[docs/TESTING.md](docs/TESTING.md)** for the full testing strategy, base c
 ```bash
 make install              # Full build
 make skip-docker          # Skip Docker
+make test                 # Unit tests only
 make integration-tests    # Run integration tests
 make format               # Format Kotlin code
 ```