[SEQ-31] Setup script for local OP Stack devnet (#2)

* feat: Add post-create script for devnet

* doc: Add comment on devnet initialization

* feat: Switch to Justfile for installation

* fix: Justfile setup

* chore: Remove bash script

* refactor: Dramatically simplify PATH export

This also improves Foundry handling, which lets Foundry installs succeed on the first attempt

* chore: Fix Justfile syntax

* chore: Clean up Justfile to be more idiomatic

* feat: Copy justfile to home directory for devnet commands

* docs: Specify that devnet is op-devnet

In contrast to an eventual Metabased devnet

Author: WillPapper

.devcontainer/devcontainer.json

@@ -1,5 +1,5 @@
 {
-  "name": "Ubuntu Latest LTS Dev Container",
+  "name": "Metabased Dev Container",
   // From https://github.com/devcontainers/images/tree/main/src/base-ubuntu
   // The default image is pinned to Ubuntu Focal 20.04: https://github.com/devcontainers/images/blob/main/src/universal/.devcontainer/Dockerfile#L6
   "image": "mcr.microsoft.com/devcontainers/base:ubuntu-24.04",
@@ -53,6 +53,11 @@
   // Use 'forwardPorts' to make a list of ports inside the container available locally.
   // "forwardPorts": [],
 
+  // Update package lists
+  // Without this, just won't be found
+  // After that, initialize the devnet
+  "postCreateCommand": "sudo apt update && sudo apt install -y just && just -f ${containerWorkspaceFolder}/.devcontainer/justfile all",
+
   // Configure tool-specific properties.
   "customizations": {
     // Configure properties specific to VS Code.

.devcontainer/justfile

@@ -0,0 +1,31 @@
+# Add Foundry's bin directory to the PATH for all recipes
+export PATH := env_var('PATH') + ":" + env_var('HOME') + "/.foundry/bin"
+
+# Clone the Optimism repository
+clone:
+    git clone https://github.com/ethereum-optimism/optimism.git ~/optimism
+
+# Install Foundry
+install-foundry:
+    just --working-directory ~/optimism install-foundry
+
+# Initialize op-devnet
+op-devnet-up:
+    make --directory ~/optimism op-devnet-up
+    @echo "OP Devnet initialized"
+
+# Shut down devnet
+op-devnet-down:
+    make --directory ~/optimism op-devnet-down
+    @echo "OP Devnet shut down"
+
+# Run all steps in sequence
+# OP Devnet setup based on https://docs.optimism.io/chain/testing/dev-node
+all: clone install-foundry op-devnet-up op-devnet-down copy-justfile
+    @echo "Post-create script completed successfully"
+
+# Copy Justfile to ~/Metabased.justfile
+# This gives easy access to op-devnet commands after the container is created
+copy-justfile:
+    cp {{justfile()}} ~/metabased-devnet.justfile
+    @echo "Justfile copied to ~/metabased-devnet.justfile"