Add Dev Containers for one-click contributor setup

Provides PostgreSQL (pgvector/pg17), Ollama, and Ruby 3.4.7 out of the
box. Works with VS Code Dev Containers, GitHub Codespaces, and JetBrains.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pjurewicz

.devcontainer/Dockerfile

@@ -0,0 +1,12 @@
+FROM ruby:3.4.7
+
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y \
+      build-essential \
+      git \
+      libpq-dev \
+      libyaml-dev \
+      postgresql-client && \
+    rm -rf /var/lib/apt/lists /var/cache/apt/archives
+
+WORKDIR /workspace

.devcontainer/devcontainer.json

@@ -0,0 +1,15 @@
+{
+  "name": "Planet",
+  "dockerComposeFile": "docker-compose.yml",
+  "service": "app",
+  "workspaceFolder": "/workspace",
+  "forwardPorts": [3000],
+  "postCreateCommand": "bundle install && bin/rails db:prepare && bin/rails db:seed",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "Shopify.ruby-lsp"
+      ]
+    }
+  }
+}

.devcontainer/docker-compose.yml

@@ -0,0 +1,38 @@
+services:
+  app:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    command: sleep infinity
+    volumes:
+      - ..:/workspace:cached
+      - bundle-cache:/usr/local/bundle
+    ports:
+      - "3000:3000"
+    environment:
+      DB_HOST: postgres
+      DB_USER: postgres
+      DB_PASSWORD: postgres
+      OLLAMA_URL: http://ollama:11434
+    depends_on:
+      - postgres
+      - ollama
+
+  postgres:
+    image: pgvector/pgvector:pg17
+    volumes:
+      - postgres-data:/var/lib/postgresql/data
+      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+
+  ollama:
+    image: ollama/ollama:latest
+    volumes:
+      - ollama-models:/root/.ollama
+
+volumes:
+  postgres-data:
+  bundle-cache:
+  ollama-models:

.devcontainer/init.sql

@@ -0,0 +1,14 @@
+CREATE EXTENSION IF NOT EXISTS vector;
+
+CREATE DATABASE planet_development_queue;
+CREATE DATABASE planet_test;
+CREATE DATABASE planet_test_queue;
+
+\c planet_development_queue
+CREATE EXTENSION IF NOT EXISTS vector;
+
+\c planet_test
+CREATE EXTENSION IF NOT EXISTS vector;
+
+\c planet_test_queue
+CREATE EXTENSION IF NOT EXISTS vector;