Update setup instructions

app/AGENTS.md

@@ -2,6 +2,18 @@
 
 The Flutter application provides a web interface for managing Typewriter projects.
 
+## Environment Setup
+
+On Linux install Flutter once by running:
+
+```bash
+./install_flutter_linux.sh
+```
+
+Run this script before executing any Flutter commands.
+It adds `~/development/flutter/bin` to your `PATH`, so open a new shell or run
+`source ~/.bashrc` after installation.
+
 ## Validate Changes
 
 Install dependencies and build the web app:

app/install_flutter_linux.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Install Flutter for Linux
+FLUTTER_VERSION="${FLUTTER_VERSION:-3.33.0-0.2.pre-beta}"
+ARCHIVE="flutter_linux_${FLUTTER_VERSION}.tar.xz"
+
+mkdir -p ~/development
+cd ~/development
+
+sudo apt-get update -y && sudo apt-get upgrade -y
+sudo apt-get install -y curl git unzip xz-utils zip libglu1-mesa
+
+if [ ! -f "$ARCHIVE" ]; then
+  wget "https://storage.googleapis.com/flutter_infra_release/releases/beta/linux/${ARCHIVE}"
+fi
+
+tar xf "$ARCHIVE"
+
+sudo chmod 777 -R ~/development
+git config --global --add safe.directory ~/development/flutter
+
+export PATH="$PATH:$(pwd)/flutter/bin"
+grep -qxF 'export PATH="$HOME/development/flutter/bin:$PATH"' ~/.bashrc || echo 'export PATH="$HOME/development/flutter/bin:$PATH"' >> ~/.bashrc
+
+echo "Flutter installed. Restart your shell or run 'source ~/.bashrc' to use it."

documentation/AGENTS.md

@@ -2,6 +2,14 @@
 
 This folder contains the Docusaurus website. Documentation and blog posts are written in Markdown/MDX.
 
+## Setup
+
+Install dependencies once with:
+
+```bash
+npm ci
+```
+
 ## Validate Changes
 
 Before committing documentation updates make sure the site builds: