Setup dev container and MCP infrastructure

Add dev container configuration with docker-compose, Dockerfile, and entrypoint script

- Create .devcontainer/devcontainer.json for VS Code dev container
- Create .devcontainer/docker-compose.yml for container setup
- Add Dockerfile with Python, Go, Rust, R, and jj tools
- Add docker-entrypoint.sh to initialize .ai_index and start mcp-server
- Add Makefile for container management and MCP operations
- Add .gitignore entries for AI index
- Add OpenCode global instructions
- Add basic MCP server and tool for listing Go imports
- Add Zed integration configuration
- Update README with project vision and structure

docker-entrypoint.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+# docker-entrypoint.sh
+
+if [ ! -d "/workspace/.ai_index" ]; then
+    mkdir -p /workspace/.ai_index/ast
+    mkdir -p /workspace/.ai_index/embeddings
+    touch /workspace/.ai_index/graph.db
+fi
+
+/opt/bin/mcp-server > /workspace/.ai_index/mcp.log 2>&1 &
+MCP_PID=$!
+echo $MCP_PID > /workspace/.ai_index/mcp.pid
+
+exec "$@"