P3.1: iOS goldens @2x + PNG optimizer + Makefile record/verify targets

- SnapshotGalleryTests rendered at displayScale: 2.0 (was native 3.0)
  → 49MB → 15MB (~69% reduction)
- Records via SNAPSHOT_TESTING_RECORD=1 env var (no code edits needed)
- scripts/optimize_goldens.sh runs zopflipng (or pngcrush fallback)
  over both iOS and Android golden dirs
- scripts/{record,verify}_snapshots.sh one-command wrappers
- Makefile targets: make {record,verify,optimize}-snapshots

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/record_snapshots.sh

@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+#
+# record_snapshots.sh — regenerate every parity-gallery golden in one pass.
+#
+# Use this after an intentional UI change (new color token, redesigned
+# layout, etc.) so the committed baseline matches the new look. Reviewers
+# see the PNG diff alongside your code change in the PR — that dual-diff
+# is the whole point of the parity gallery.
+#
+# Usage
+# -----
+#   ./scripts/record_snapshots.sh                # iOS + Android
+#   ./scripts/record_snapshots.sh --ios-only
+#   ./scripts/record_snapshots.sh --android-only
+#
+# Pipeline
+# --------
+#   1. (Android) `./gradlew :composeApp:recordRoborazziDebug`
+#   2. (iOS)     Delete iosApp/HoneyDueTests/__Snapshots__/SnapshotGalleryTests,
+#                set SNAPSHOT_TESTING_RECORD=1, run xcodebuild test for
+#                SnapshotGalleryTests. The env var is read by
+#                SnapshotGalleryTests.swift to flip SnapshotTesting.record
+#                between `.missing` (default — safe) and `.all` (overwrite).
+#   3. Run `scripts/optimize_goldens.sh` across both golden directories to
+#      shrink the fresh PNGs.
+#
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+ROOT="$(pwd)"
+
+platform="both"
+for arg in "$@"; do
+    case "$arg" in
+        --ios-only)     platform="ios" ;;
+        --android-only) platform="android" ;;
+        -h|--help)
+            sed -n '3,18p' "$0"
+            exit 0
+            ;;
+        *)
+            echo "usage: $0 [--ios-only|--android-only]" >&2
+            exit 1
+            ;;
+    esac
+done
+
+# ---------- Android ----------
+if [ "$platform" = "both" ] || [ "$platform" = "android" ]; then
+    echo "==> Recording Android goldens…"
+    ./gradlew :composeApp:recordRoborazziDebug
+fi
+
+# ---------- iOS ----------
+if [ "$platform" = "both" ] || [ "$platform" = "ios" ]; then
+    echo "==> Recording iOS goldens…"
+    rm -rf iosApp/HoneyDueTests/__Snapshots__/SnapshotGalleryTests
+    (
+        cd iosApp
+        # SNAPSHOT_TESTING_RECORD=1 flips SnapshotTesting.isRecording to
+        # `.all` (see SnapshotGalleryTests.swift).
+        SNAPSHOT_TESTING_RECORD=1 xcodebuild test \
+            -project honeyDue.xcodeproj \
+            -scheme HoneyDue \
+            -destination "${IOS_SIM_DESTINATION:-platform=iOS Simulator,name=iPhone 17,OS=latest}" \
+            -only-testing:HoneyDueTests/SnapshotGalleryTests \
+            2>&1 | tail -30
+    )
+fi
+
+# ---------- Optimize ----------
+echo "==> Optimizing PNGs…"
+"$ROOT/scripts/optimize_goldens.sh"
+
+# ---------- Parity HTML (P4 follow-up) ----------
+if [ -x "$ROOT/scripts/build_parity_gallery.py" ]; then
+    echo "==> Regenerating parity HTML gallery…"
+    python3 "$ROOT/scripts/build_parity_gallery.py"
+else
+    echo "==> (parity HTML generator not yet present — skipping)"
+fi
+
+echo "==> Done. Review the PNG diff with your code change before committing."