fix docker: APK in dist/ invece di output/

Rimuove la cartella output/ e monta dist/ in lettura/scrittura
così l'APK viene scritto direttamente in dist/biteplan.apk

docker/build.sh

@@ -3,7 +3,6 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
-OUTPUT_DIR="$PROJECT_ROOT/output"
 DIST_DIR="$PROJECT_ROOT/dist"
 
 FROM_HEAD=false
@@ -11,9 +10,6 @@ for arg in "$@"; do
   [[ "$arg" == "--head" ]] && FROM_HEAD=true
 done
 
-echo "==> Preparazione cartelle..."
-mkdir -p "$OUTPUT_DIR"
-
 # ── Build Vite ────────────────────────────────────────────────────────────────
 if $FROM_HEAD; then
   COMMIT_SHA=$(git -C "$PROJECT_ROOT" rev-parse --short HEAD)
@@ -43,9 +39,8 @@ docker build \
 # ── Generazione APK (dist/ montato come volume) ───────────────────────────────
 echo "==> Generazione APK..."
 docker run --rm \
-    -v "$DIST_DIR:/app/dist:ro" \
-    -v "$OUTPUT_DIR:/output" \
+    -v "$DIST_DIR:/app/dist" \
     biteplan-builder
 
 echo ""
-echo "APK pronto in: $OUTPUT_DIR/biteplan.apk"
+echo "APK pronto in: $DIST_DIR/biteplan.apk"