Add devcontainer setup with Java 25, DynamoDB local, and development tools

- Configure devcontainer with Maven 3.9.11 and Java 25 LTS
- Add local DynamoDB instance for development and testing
- Install AWS CLI and Claude Code in development environment
- Create comprehensive .gitignore for Java projects on macOS
- Set up Docker Compose configuration with proper networking

Author: wassertim

.devcontainer/Dockerfile

@@ -0,0 +1,19 @@
+# Use official Maven image with Eclipse Temurin Java 25
+FROM maven:3.9.11-eclipse-temurin-25
+
+# Install unzip and other tools needed
+RUN apt-get update && apt-get install -y \
+    unzip \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Claude Code
+RUN curl -fsSL https://claude.ai/install.sh | bash
+
+# Install AWS CLI
+RUN curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip" \
+    && unzip awscliv2.zip \
+    && ./aws/install \
+    && rm -rf awscliv2.zip aws
+
+# Maven images typically run as root by default, which is fine for devcontainers

.devcontainer/devcontainer.json

@@ -0,0 +1,17 @@
+{
+  "name": "DynamoDB Toolkit Dev Environment",
+  "dockerComposeFile": "docker-compose.yml",
+  "service": "devcontainer",
+  "workspaceFolder": "/workspace",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "vscjava.vscode-java-pack",
+        "vscjava.vscode-maven",
+        "redhat.java"
+      ]
+    }
+  },
+  "postCreateCommand": "echo 'Java development environment with Claude Code ready'",
+  "remoteUser": "root"
+}

.devcontainer/docker-compose.yml

@@ -0,0 +1,24 @@
+version: '3.8'
+
+services:
+  devcontainer:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    volumes:
+      - ../..:/workspaces:cached
+    working_dir: /workspace
+    command: sleep infinity
+    depends_on:
+      - dynamodb-local
+    environment:
+      AWS_ACCESS_KEY_ID: dummy
+      AWS_SECRET_ACCESS_KEY: dummy
+      AWS_DEFAULT_REGION: us-east-1
+      DYNAMODB_ENDPOINT: http://dynamodb-local:8000
+
+  dynamodb-local:
+    image: amazon/dynamodb-local:latest
+    command: ["-jar", "DynamoDBLocal.jar", "-sharedDb", "-inMemory"]
+    ports:
+      - "8083:8000"

.gitignore

@@ -0,0 +1,116 @@
+# Claude Code
+.claude/
+
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+replay_pid*
+
+# Maven
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+.mvn/wrapper/maven-wrapper.jar
+
+# Gradle
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+# IntelliJ IDEA
+.idea/
+*.iws
+*.iml
+*.ipr
+
+# Eclipse
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+# NetBeans
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+# VS Code
+.vscode/
+
+# Mac OS
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Temporary files
+*.tmp
+*.temp
+
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# Application logs
+logs/
+*.log.*
+
+# JUnit test results
+TEST-*.xml
+
+# Coverage reports
+*.exec
+.jacoco/
+
+# Sonar
+.sonar/
+.scannerwork/
+
+# Spring Boot
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+# Node modules (if using any Node.js tools)
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*

docker-compose.yml

@@ -0,0 +1,12 @@
+version: '3.8'
+
+services:
+  dynamodb-local:
+    image: amazon/dynamodb-local:latest
+    command: ["-jar", "DynamoDBLocal.jar", "-sharedDb", "-inMemory"]
+    ports:
+      - "8000:8000"
+    environment:
+      - AWS_ACCESS_KEY_ID=dummy
+      - AWS_SECRET_ACCESS_KEY=dummy
+      - AWS_DEFAULT_REGION=us-east-1