chore: add compose alternative to develop.sh (#22157)

Adds a `compose.dev.yml` intended as a pure-Docker alternative to
`develop.sh`.

---------

Co-authored-by: Steven Masley <stevenmasley@gmail.com>

scripts/docker-dev/setup-users.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+set -e
+
+CODER="go run ./cmd/coder"
+PASSWORD="${CODER_DEV_MEMBER_PASSWORD:-SomeSecurePassword!}"
+TOKEN_FILE="/bootstrap/token"
+
+echo "=== Setting up users ==="
+
+# Load bootstrap token
+CODER_SESSION_TOKEN=$(cat "$TOKEN_FILE")
+if [ -z "${CODER_SESSION_TOKEN}" ]; then
+	echo "Bootstrap token not found in ${TOKEN_FILE}"
+	exit 1
+fi
+export CODER_SESSION_TOKEN
+
+# Create member user (idempotent)
+echo "Creating member user..."
+$CODER users create \
+	--email=member@coder.com \
+	--username=member \
+	--full-name="Regular User" \
+	--password="$PASSWORD" 2>/dev/null || echo "Member user already exists."
+
+echo "=== Users setup complete ==="