tools: add make analyze/test/doctor and unify gradle wrappers

- Add scripts/analyze_all.sh and scripts/test_all.sh that run flutter
  analyze/test across every app and report a summary
- Add scripts/repo_doctor.sh that flags config drift (sdk constraint,
  analysis_options, pubspec name, applicationId, gradle version, docs,
  tracked generated files) and exits non-zero for use as a pre-commit gate
- Wire these into the Makefile as 'make analyze/test/doctor' and document
  them in MAINTENANCE.md
- Bring bmi_calculator and push_notifications gradle wrappers up to the
  repo-standard 9.7.0; note push_notifications as a Firebase app requiring
  google-services.json

scripts/analyze_all.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Runs `flutter analyze` in every example app and reports the results.
+# Exits non-zero if any app has analyzer issues.
+
+source "$(dirname "${BASH_SOURCE[0]}")/common.sh"
+
+clean=0
+issues=0
+failed=0
+apps_with_issues=()
+
+analyze_app() {
+	local dir="$1"
+	local app
+	app=$(basename "$dir")
+
+	local out
+	if ! out=$(cd "$dir" && flutter analyze 2>&1); then
+		failed=$((failed + 1))
+		return
+	fi
+
+	local summary
+	summary=$(echo "$out" | tail -1)
+	if echo "$out" | grep -q "No issues found"; then
+		clean=$((clean + 1))
+	else
+		issues=$((issues + 1))
+		apps_with_issues+=("$app")
+		printf "  %-30s %s\n" "$app" "$summary"
+	fi
+}
+
+separator
+echo "  Running flutter analyze for all Flutter apps:"
+for_each_app pubspec.yaml analyze_app
+separator
+printf "  %-16s %s\n" "Clean:" "$clean"
+printf "  %-16s %s\n" "With issues:" "$issues"
+printf "  %-16s %s\n" "Failed to run:" "$failed"
+if [ "${#apps_with_issues[@]}" -gt 0 ]; then
+	echo "  Apps with issues:"
+	printf "    %s\n" "${apps_with_issues[@]}"
+fi
+separator
+
+[ "$issues" -eq 0 ] && [ "$failed" -eq 0 ]