diff --git a/scripts/uat.sh b/scripts/uat.sh
index 965b2814..bab7f465 100755
--- a/scripts/uat.sh
+++ b/scripts/uat.sh
@@ -34,7 +34,7 @@ cd "$ROOT_DIR"
 RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; BOLD='\033[1m'; NC='\033[0m'
 info()  { echo -e "${GREEN}[INFO]${NC} $*"; }
 warn()  { echo -e "${YELLOW}[WARN]${NC} $*"; }
-error() { echo -e "${RED}[ERROR]${NC} $*"; exit 1; }
+error() { echo -e "${RED}[ERROR]${NC} $*" >&2; exit 1; }
 
 DO_IOS=1; DO_ANDROID=1
 case "${1:-}" in
@@ -46,12 +46,12 @@ esac
 command -v node   >/dev/null || error "node not installed"
 command -v gh     >/dev/null || error "gh CLI not installed"
 command -v bundle >/dev/null || error "bundler not installed (bundle install)"
-[ -f fastlane/Fastfile ]     || error "fastlane/Fastfile not found"
+[[ -f fastlane/Fastfile ]]   || error "fastlane/Fastfile not found"
 # Ignore fastlane/README.md — fastlane regenerates it on every run, so it is dirty by the time a
 # second build starts (and after any prior run). It is not source we build from.
-[ -z "$(git status --porcelain | grep -vE 'fastlane/README\.md$' || true)" ] || error "Working tree is dirty. Commit or stash first."
-[ "$DO_ANDROID" = 0 ] || { [ -f android/gradlew ] || error "android/gradlew not found"; [ -n "${ANDROID_HOME:-}" ] || error "ANDROID_HOME not set"; }
-[ "$DO_IOS" = 0 ]     || command -v xcodebuild >/dev/null || error "xcodebuild not installed"
+[[ -z "$(git status --porcelain | grep -vE 'fastlane/README\.md$' || true)" ]] || error "Working tree is dirty. Commit or stash first."
+[[ "$DO_ANDROID" = 0 ]] || { [[ -f android/gradlew ]] || error "android/gradlew not found"; [[ -n "${ANDROID_HOME:-}" ]] || error "ANDROID_HOME not set"; }
+[[ "$DO_IOS" = 0 ]]     || command -v xcodebuild >/dev/null || error "xcodebuild not installed"
 
 # ── compute the beta version ───────────────────────────────────────
 # A beta targets the NEXT version, not the live one (the live train is closed - see header).
@@ -70,7 +70,7 @@ BUILD_NUMBER=$(date +%s)
 info "Beta build: ${BOLD}${BETA_VERSION}${NC} (build ${BUILD_NUMBER}) - pre-release of ${TARGET_VERSION} (current live: ${CURRENT_VERSION})"
 
 # ── apply the build-number / beta-versionName bump (working tree; committed only on success) ──
-if [ "$DO_ANDROID" = 1 ]; then
+if [[ "$DO_ANDROID" = 1 ]]; then
   sed -i '' "s/versionCode .*/versionCode $BUILD_NUMBER/" android/app/build.gradle
   # versionName = the PRODUCTION version (no -beta suffix), matching iOS's MARKETING_VERSION
   # below. versionName is frozen into the AAB and is user-visible, so a "-beta" suffix here
@@ -80,7 +80,7 @@ if [ "$DO_ANDROID" = 1 ]; then
   # "-beta.N" label lives in the git tag, the GitHub prerelease, and the store release notes.
   sed -i '' "s/versionName .*/versionName \"$TARGET_VERSION\"/" android/app/build.gradle
 fi
-if [ "$DO_IOS" = 1 ]; then
+if [[ "$DO_IOS" = 1 ]]; then
   # iOS marketing version = NEXT plain numeric version (App Store rejects "-beta", and this
   # opens a fresh TestFlight train since the live version's train is closed); build no. bumps.
   sed -i '' "s/MARKETING_VERSION = .*/MARKETING_VERSION = $TARGET_VERSION;/" ios/OffgridMobile.xcodeproj/project.pbxproj
@@ -109,7 +109,7 @@ gen_notes_with_claude() {
     2>/dev/null
 }
 
-if NOTES=$(gen_notes_with_claude) && [ -n "$NOTES" ]; then
+if NOTES=$(gen_notes_with_claude) && [[ -n "$NOTES" ]]; then
   printf '%s\n' "$NOTES" > "$NOTES_FILE"
   info "Release notes generated by claude -p"
 else
@@ -132,29 +132,29 @@ info "Notes:"; sed 's/^/    /' "$NOTES_FILE"; echo ""
 # every retry). So we build ALL artifacts up front - the steps that actually fail (compile,
 # signing, export) happen before a single upload - and only publish once every artifact
 # exists. The fastlane beta lanes read UAT_CHANGELOG_PATH at upload time.
-if [ "$DO_ANDROID" = 1 ]; then
+if [[ "$DO_ANDROID" = 1 ]]; then
   info "Android → building signed AAB…"; bundle exec fastlane android build
   # Also build the sideloadable APK for the GitHub prerelease (the AAB isn't installable;
   # testers grabbing the build off GitHub need the APK - same as scripts/release.sh).
   info "Android → building installable APK for GitHub…"; (cd android && ./gradlew assembleRelease)
   AAB_SRC="android/app/build/outputs/bundle/release/app-release.aab"
   APK_SRC="android/app/build/outputs/apk/release/app-release.apk"
-  [ -f "$AAB_SRC" ] || error "AAB not found at $AAB_SRC"
-  [ -f "$APK_SRC" ] || error "APK not found at $APK_SRC"
+  [[ -f "$AAB_SRC" ]] || error "AAB not found at $AAB_SRC"
+  [[ -f "$APK_SRC" ]] || error "APK not found at $APK_SRC"
 fi
-if [ "$DO_IOS" = 1 ]; then
+if [[ "$DO_IOS" = 1 ]]; then
   info "iOS → building signed IPA…"; bundle exec fastlane ios build
-  [ -f build/OffgridMobile.ipa ] || error "IPA not found at build/OffgridMobile.ipa"
+  [[ -f build/OffgridMobile.ipa ]] || error "IPA not found at build/OffgridMobile.ipa"
 fi
 
 # ── PUBLISH - reached only if every build above succeeded ───────────
-if [ "$DO_ANDROID" = 1 ]; then info "Android → Play internal (AAB)…"; bundle exec fastlane android upload_beta; fi
-if [ "$DO_IOS" = 1 ];     then info "iOS → TestFlight…";              bundle exec fastlane ios upload_beta;     fi
+if [[ "$DO_ANDROID" = 1 ]]; then info "Android → Play internal (AAB)…"; bundle exec fastlane android upload_beta; fi
+if [[ "$DO_IOS" = 1 ]];     then info "iOS → TestFlight…";              bundle exec fastlane ios upload_beta;     fi
 
 # ── success → commit the bump, cut the PRERELEASE tag, GH prerelease ──
 trap - EXIT   # keep the bump now that the build shipped
-FILES=(); [ "$DO_ANDROID" = 1 ] && FILES+=(android/app/build.gradle)
-[ "$DO_IOS" = 1 ] && FILES+=(ios/OffgridMobile.xcodeproj/project.pbxproj)
+FILES=(); [[ "$DO_ANDROID" = 1 ]] && FILES+=(android/app/build.gradle)
+[[ "$DO_IOS" = 1 ]] && FILES+=(ios/OffgridMobile.xcodeproj/project.pbxproj)
 git add "${FILES[@]}"
 git commit -m "chore(beta): ${BETA_VERSION} (build ${BUILD_NUMBER}) [skip ci]"
 # Annotate the tag with the tested store build id (Android versionCode / iOS
@@ -173,10 +173,10 @@ git push && git push origin "$TAG"
 GH_ARGS=()
 APK_DST="$ROOT_DIR/OffgridMobile-${BETA_VERSION}.apk"
 AAB_DST="$ROOT_DIR/OffgridMobile-${BETA_VERSION}.aab"
-if [ "$DO_ANDROID" = 1 ]; then
-  [ -f android/app/build/outputs/apk/release/app-release.apk ] && \
+if [[ "$DO_ANDROID" = 1 ]]; then
+  [[ -f android/app/build/outputs/apk/release/app-release.apk ]] && \
     { cp android/app/build/outputs/apk/release/app-release.apk "$APK_DST"; GH_ARGS+=("$APK_DST"); }
-  [ -f android/app/build/outputs/bundle/release/app-release.aab ] && \
+  [[ -f android/app/build/outputs/bundle/release/app-release.aab ]] && \
     { cp android/app/build/outputs/bundle/release/app-release.aab "$AAB_DST"; GH_ARGS+=("$AAB_DST"); }
 fi
 # Carry the tested build id into the prerelease body too (redundant with the annotated tag),
@@ -195,7 +195,7 @@ SLACK_WEBHOOK_URL="${SLACK_WEBHOOK_URL:-$(sed -n 's/^SLACK_WEBHOOK_URL=//p' "$RO
 rm -f "$NOTES_FILE" "${ANDROID_CHANGELOG:-}" "$APK_DST" "$AAB_DST"
 echo ""
 info "${BOLD}Beta ${BETA_VERSION} shipped.${NC}"
-[ "$DO_IOS" = 1 ]     && info "  iOS:     TestFlight (App Store Connect → TestFlight)"
-[ "$DO_ANDROID" = 1 ] && info "  Android: Play Console → Internal testing"
+[[ "$DO_IOS" = 1 ]]     && info "  iOS:     TestFlight (App Store Connect → TestFlight)"
+[[ "$DO_ANDROID" = 1 ]] && info "  Android: Play Console → Internal testing"
 info "  GitHub:  $(gh release view "$TAG" --json url -q .url 2>/dev/null)"
 info "Approve the beta, then run scripts/release.sh to cut the real version to production."