fix: run-builder.sh uses BUILDER_USER from .env, not hardcoded

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

.env.example

@@ -1 +1,2 @@
 BUILDER_HOST=
+BUILDER_USER=

scripts/run-builder.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# run-builder.sh — trigger debug ISO build on remote Alpine builder VM
+# run-builder.sh — trigger ISO build on remote Debian 12 builder VM
 #
 # Usage:
 #   sh scripts/run-builder.sh
@@ -18,10 +18,15 @@ if [ -f "$ENV_FILE" ]; then
 fi
 
 BUILDER_HOST="${BUILDER_HOST:-}"
+BUILDER_USER="${BUILDER_USER:-}"
 if [ -z "$BUILDER_HOST" ]; then
     echo "ERROR: BUILDER_HOST not set. Copy .env.example to .env and set the address."
     exit 1
 fi
+if [ -z "$BUILDER_USER" ]; then
+    echo "ERROR: BUILDER_USER not set. Set it in .env."
+    exit 1
+fi
 
 EXTRA_ARGS=""
 while [ $# -gt 0 ]; do
@@ -32,7 +37,7 @@ while [ $# -gt 0 ]; do
 done
 
 echo "=== bee builder ==="
-echo "Builder: ${BUILDER_HOST}"
+echo "Builder: ${BUILDER_USER}@${BUILDER_HOST}"
 echo ""
 
 # --- check local repo is in sync with remote ---
@@ -53,10 +58,10 @@ fi
 echo "repo: in sync with remote ($LOCAL)"
 echo ""
 
-ssh -o StrictHostKeyChecking=no root@"${BUILDER_HOST}" /bin/sh <<ENDSSH
+ssh -o StrictHostKeyChecking=no "${BUILDER_USER}@${BUILDER_HOST}" /bin/sh <<ENDSSH
 set -e
-REPO=/root/bee
-LOG=/var/log/bee-build.log
+REPO="/home/${BUILDER_USER}/bee"
+LOG=/tmp/bee-build.log
 
 if [ ! -d "\$REPO/.git" ]; then
     echo "--- cloning bee repo ---"
@@ -67,24 +72,25 @@ cd "\$REPO"
 echo "--- pulling latest ---"
 git checkout -- .
 git pull --ff-only
-chmod +x iso/overlay/etc/init.d/* iso/overlay/usr/local/bin/* 2>/dev/null || true
+chmod +x iso/overlay/usr/local/bin/* 2>/dev/null || true
 
 # Kill any previous build session
 screen -S bee-build -X quit 2>/dev/null || true
 
 echo "--- starting build in screen session (survives SSH disconnect) ---"
 echo "--- log: \$LOG ---"
-screen -dmS bee-build sh -c "sh iso/builder/build.sh ${EXTRA_ARGS} > \$LOG 2>&1; echo \$? > /tmp/bee-build-exit"
+screen -dmS bee-build sh -c "sudo sh iso/builder/build.sh ${EXTRA_ARGS} > \$LOG 2>&1; echo \$? > /tmp/bee-build-exit"
 
 # Stream log until build finishes
 echo "--- streaming build log (Ctrl+C safe — build continues on VM) ---"
-while screen -list | grep -q bee-build; do
-    tail -n +1 -f "\$LOG" 2>/dev/null & TAIL_PID=\$!
-    sleep 1
-    while screen -list | grep -q bee-build; do sleep 2; done
-    kill \$TAIL_PID 2>/dev/null || true
-    break
+tail -n +1 -f "\$LOG" 2>/dev/null &
+TAIL_PID=\$!
+while screen -list 2>/dev/null | grep -q bee-build; do
+    sleep 2
 done
+sleep 1
+kill \$TAIL_PID 2>/dev/null || true
+
 tail -n 20 "\$LOG" 2>/dev/null || true
 
 EXIT_CODE=\$(cat /tmp/bee-build-exit 2>/dev/null || echo 1)
@@ -95,14 +101,14 @@ echo ""
 echo "=== downloading ISO ==="
 LOCAL_ISO_DIR="${REPO_ROOT}/iso/out"
 mkdir -p "${LOCAL_ISO_DIR}"
-if command -v rsync >/dev/null 2>&1 && ssh -o StrictHostKeyChecking=no root@"${BUILDER_HOST}" command -v rsync >/dev/null 2>&1; then
+if command -v rsync >/dev/null 2>&1 && ssh -o StrictHostKeyChecking=no "${BUILDER_USER}@${BUILDER_HOST}" command -v rsync >/dev/null 2>&1; then
     rsync -az --progress \
         -e "ssh -o StrictHostKeyChecking=no" \
-        "root@${BUILDER_HOST}:/root/bee/dist/*.iso" \
+        "${BUILDER_USER}@${BUILDER_HOST}:/home/${BUILDER_USER}/bee/dist/*.iso" \
         "${LOCAL_ISO_DIR}/"
 else
     scp -o StrictHostKeyChecking=no \
-        "root@${BUILDER_HOST}:/root/bee/dist/*.iso" \
+        "${BUILDER_USER}@${BUILDER_HOST}:/home/${BUILDER_USER}/bee/dist/*.iso" \
         "${LOCAL_ISO_DIR}/"
 fi
 echo ""