Add devcontainer environment and CI

.devcontainer/Dockerfile

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+FROM mcr.microsoft.com/devcontainers/base:trixie
+
+# Install libaio1t64 and provide a libaio.so.1 symlink for Oracle Instant Client
+# Install rlwrap for readline support in sqlplus
+RUN rm -f /etc/apt/sources.list.d/yarn.list \
+    && apt-get update \
+    && apt-get install -y libaio1t64 rlwrap \
+    && rm -rf /var/lib/apt/lists/* \
+    && DEB_HOST_MULTIARCH="$(dpkg-architecture -qDEB_HOST_MULTIARCH)" \
+    && ln -sf /usr/lib/${DEB_HOST_MULTIARCH}/libaio.so.1t64 \
+              /usr/lib/${DEB_HOST_MULTIARCH}/libaio.so.1 \
+    && echo "alias sqlplus='rlwrap sqlplus'" >> /etc/bash.bashrc
+
+# Create directory structure for Oracle
+RUN mkdir -p /opt/oracle
+
+# Download and install Oracle Instant Client based on architecture.
+# x86_64 uses Oracle's version-less "always latest" URLs; arm64 must pin a
+# version because Oracle does not publish version-less arm64 zips.
+WORKDIR /tmp
+RUN ARCH=$(uname -m) && \
+    if [ "$ARCH" = "aarch64" ] || [ "$ARCH" = "arm64" ]; then \
+        IC_VERSION="23.26.1.0.0"; \
+        IC_PATH="2326100"; \
+        BASE_URL="https://download.oracle.com/otn_software/linux/instantclient/${IC_PATH}"; \
+        BASIC="instantclient-basic-linux.arm64-${IC_VERSION}.zip"; \
+        SDK="instantclient-sdk-linux.arm64-${IC_VERSION}.zip"; \
+        SQLPLUS="instantclient-sqlplus-linux.arm64-${IC_VERSION}.zip"; \
+    else \
+        BASE_URL="https://download.oracle.com/otn_software/linux/instantclient"; \
+        BASIC="instantclient-basic-linuxx64.zip"; \
+        SDK="instantclient-sdk-linuxx64.zip"; \
+        SQLPLUS="instantclient-sqlplus-linuxx64.zip"; \
+    fi && \
+    wget -q "${BASE_URL}/${BASIC}" \
+    && wget -q "${BASE_URL}/${SDK}" \
+    && wget -q "${BASE_URL}/${SQLPLUS}" \
+    && unzip -qo "${BASIC}" \
+    && unzip -qo "${SDK}" \
+    && unzip -qo "${SQLPLUS}" \
+    && mv instantclient_*/ /opt/oracle/instantclient \
+    && rm -f instantclient-*.zip
+
+# Set Oracle environment variables
+ENV ORACLE_HOME=/opt/oracle/instantclient \
+    LD_LIBRARY_PATH=/opt/oracle/instantclient:$LD_LIBRARY_PATH \
+    PATH=/opt/oracle/instantclient:$PATH
+
+# Switch to vscode user
+USER vscode
+
+# Set working directory
+WORKDIR /workspaces/ruby-plsql

.devcontainer/devcontainer.json

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+{
+  "name": "Ruby PL/SQL",
+  "dockerComposeFile": "docker-compose.yml",
+  "service": "app",
+  "workspaceFolder": "/workspaces/ruby-plsql",
+  "features": {
+    "ghcr.io/rails/devcontainer/features/ruby:2": {
+      "version": "4.0.3"
+    }
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "shopify.ruby-lsp"
+      ]
+    }
+  },
+  "initializeCommand": "docker pull gvenzl/oracle-free:latest",
+  "postCreateCommand": "bash .devcontainer/postCreateCommand.sh",
+  "remoteEnv": {
+    "DATABASE_NAME": "FREEPDB1",
+    "DATABASE_SYS_PASSWORD": "Oracle18",
+    "NLS_LANG": "American_America.AL32UTF8",
+    "TNS_ADMIN": "/workspaces/ruby-plsql/ci/network/admin",
+    "TWO_TASK": "FREEPDB1"
+  },
+  "remoteUser": "vscode",
+  "mounts": [
+    "source=${localWorkspaceFolder}/.bundle,target=/home/vscode/.bundle,type=bind,consistency=delegated"
+  ]
+}

.devcontainer/docker-compose.yml

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+services:
+  app:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    volumes:
+      - ../..:/workspaces:cached
+    command: sleep infinity
+    network_mode: service:oracle
+
+  oracle:
+    image: gvenzl/oracle-free:latest
+    ports:
+      - "1521:1521"
+    environment:
+      TZ: Europe/Riga
+      ORACLE_PASSWORD: Oracle18
+    healthcheck:
+      test: ["CMD", "healthcheck.sh"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+    volumes:
+      - oracle-data:/opt/oracle/oradata
+
+volumes:
+  oracle-data:

.devcontainer/postCreateCommand.sh

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+#!/bin/bash
+
+set -e
+
+gem update --system
+bundle install
+
+echo "Waiting for Oracle to be ready..."
+oracle_ready=false
+for i in $(seq 1 30); do
+  if echo "exit" | sqlplus -s "system/${DATABASE_SYS_PASSWORD}@${DATABASE_NAME}" > /dev/null 2>&1; then
+    oracle_ready=true
+    break
+  fi
+  echo "Attempt $i/30 failed, retrying in 10s..."
+  sleep 10
+done
+if [ "$oracle_ready" != "true" ]; then
+  echo "Oracle did not become ready after 30 attempts; aborting container setup." >&2
+  exit 1
+fi
+
+ci/setup_accounts.sh
+
+echo "Dev container setup complete. You are ready to start developing ruby-plsql!"

.github/workflows/devcontainer.yml

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+name: devcontainer
+
+on:
+  schedule:
+    - cron: "0 6 1 * *"  # 1st of every month at 6:00 AM UTC
+  workflow_dispatch:
+
+env:
+  RUBYOPT: "-w"
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Ensure .bundle mount source exists
+        run: mkdir -p .bundle
+
+      - name: Boot dev container and run tests
+        uses: devcontainers/ci@v0.3
+        with:
+          runCmd: |
+            uname -a
+            lsb_release -a
+            ruby --version
+            bundle exec rake spec
+            bundle exec rubocop