Add Pokemon Crystal as a sixth supported version

Crystal boots from a user-supplied ROM, imports a full cache and is playable:
copyright, the Crystal intro movie, the animated title, gender select, Oak,
and out into Johto. 122 of the cart's 169 script specials are implemented.

Import and data
- tools/make_crystal_manifest.py derives the manifest by importing
  make_gold_manifest as a library, with three additive keyword seams. Gold and
  Silver still regenerate byte-identical, which is the standing requirement for
  touching that generator.
- crystal_symbol_deltas.py and crystal_movie_symbols.py carry the symbol delta:
  Crystal renames the credits mons, splits the trainer card, Pokegear and
  pack-pal blocks by gender, and replaces the intro and title outright.
- Crystal-only manifest keys: engineFlagOrder (162 flags to Gold's 93, so the
  badge block sits one higher) and unownCharmap (the main charmap parser stops
  at the first newcharmap so the two cannot contaminate each other).

Extractor
- RomExtractorGen2 becomes three-edition. Crystal corrections: PAL_MAP_BANK
  0x13, a flat PICS_FIX pic bank, audio bank 0x5e, the mapSongs id-100 hole,
  seven NPC trades, a TradeTexts stride of 8, the five Crystal tileset anim
  steps with per-row degrade, and the column-major trainer card portraits.
- New: animated front sprites (frames, bitmasks, play and idle scripts), the
  Battle Tower roster, Kris assets, Mobile System GB art, and the Crystal
  intro and title via src/import/CrystalMovie.lua.

Engine
- GameVersion gains engine(id) and fixes(id). Gold and Silver keep their
  original bugs where the bug is not hardware dependent; Crystal gets the fixes
  Crystal shipped: Lucky Number boxes 10-14, surfing onto an NPC, and the
  Reflect and Light Screen defence overflow.
- Crystal story: Suicune and Eusine, Celebi behind the GS Ball flag, the Ruins
  of Alph chambers, Buena, the Move Tutor, the Poke Seer, and the Battle Tower
  including the wInBattleTowerBattle badge-boost guard.
- Kris and the gender flag, animated fronts in battle and the summary screen,
  and mon caught data.

Verification
- Every extracted asset is pixel-compared against pret's own source PNGs.
- Gold caches are byte-identical before and after, file for file.
- New Crystal suites plus a T2 Gen 2 tier; the full suite passes.

scripts/build_android.sh

@@ -34,6 +34,8 @@ GOLD_MANIFEST_RELATIVE="tools/rom_manifest_gold.json"
 GOLD_MANIFEST_URL="${GOLD_MANIFEST_URL:-https://raw.githubusercontent.com/bryanthaboi/gen1recomp/main/tools/rom_manifest_gold.json}"
 SILVER_MANIFEST_RELATIVE="tools/rom_manifest_silver.json"
 SILVER_MANIFEST_URL="${SILVER_MANIFEST_URL:-https://raw.githubusercontent.com/bryanthaboi/gen1recomp/main/tools/rom_manifest_silver.json}"
+CRYSTAL_MANIFEST_RELATIVE="tools/rom_manifest_crystal.json"
+CRYSTAL_MANIFEST_URL="${CRYSTAL_MANIFEST_URL:-https://raw.githubusercontent.com/bryanthaboi/gen1recomp/main/tools/rom_manifest_crystal.json}"
 
 VERSION=""
 PACKAGE_ONLY=false
@@ -246,6 +248,54 @@ ensure_silver_manifest() {
   fail "Silver import manifest is unavailable. Git recovery failed and could not download $SILVER_MANIFEST_URL"
 }
 
+crystal_manifest_is_valid() {
+  local path="$1"
+  python3 - "$path" <<'PY'
+import json, pathlib, sys
+
+try:
+    manifest = json.loads(pathlib.Path(sys.argv[1]).read_text())
+except (OSError, ValueError):
+    raise SystemExit(1)
+
+raise SystemExit(0 if manifest.get("romSha1") ==
+                 "f4cd194bdee0d04ca4eac29e09b8e4e9d818c133" else 1)
+PY
+}
+
+ensure_crystal_manifest() {
+  local manifest="$ROOT/$CRYSTAL_MANIFEST_RELATIVE"
+  local staged
+  staged="$(mktemp)"
+
+  if crystal_manifest_is_valid "$manifest"; then
+    rm -f "$staged"
+    return
+  fi
+
+  warn "Crystal import manifest is missing or invalid; recovering it before packaging"
+  if git -C "$ROOT" show "HEAD:$CRYSTAL_MANIFEST_RELATIVE" > "$staged" 2>/dev/null \
+      && crystal_manifest_is_valid "$staged"; then
+    mkdir -p "$(dirname "$manifest")"
+    mv "$staged" "$manifest"
+    say "restored Crystal import manifest from this checkout's Git data"
+    return
+  fi
+
+  if command -v curl >/dev/null 2>&1 \
+      && curl --fail --location --retry 2 --connect-timeout 15 \
+          --output "$staged" "$CRYSTAL_MANIFEST_URL" \
+      && crystal_manifest_is_valid "$staged"; then
+    mkdir -p "$(dirname "$manifest")"
+    mv "$staged" "$manifest"
+    say "downloaded Crystal import manifest from the project repository"
+    return
+  fi
+
+  rm -f "$staged"
+  fail "Crystal import manifest is unavailable. Git recovery failed and could not download $CRYSTAL_MANIFEST_URL"
+}
+
 # --------------------------------------------------------------- branding
 # love-android 11.5+ reads app id / name / orientation from gradle.properties.
 # Manifest still gets permission trims. Re-applied every build so refreshing
@@ -312,6 +362,7 @@ pack_game_love() {
   ensure_yellow_manifest
   ensure_gold_manifest
   ensure_silver_manifest
+  ensure_crystal_manifest
   mkdir -p "$EMBED_ASSETS"
   rm -f "$LOVE_FILE"
   # tools/save-editor ships with the app: the launcher's Edit button on a save
@@ -326,7 +377,7 @@ pack_game_love() {
     main.lua conf.lua src data assets tools/save-editor \
     tools/rom_manifest.json tools/rom_manifest_blue.json \
     tools/rom_manifest_yellow.json tools/rom_manifest_gold.json \
-    tools/rom_manifest_silver.json \
+    tools/rom_manifest_silver.json tools/rom_manifest_crystal.json \
     -x '*.DS_Store' -x '*/.git/*' -x '*/.DS_Store' \
     -x 'data/generated/*' -x 'assets/generated/*')
   # List once and match against the captured text: piping unzip straight into
@@ -350,6 +401,8 @@ pack_game_love() {
     || fail "game.love is missing the Gold ROM import manifest"
   grep -qx 'tools/rom_manifest_silver.json' <<< "$archive_entries" \
     || fail "game.love is missing the Silver ROM import manifest"
+  grep -qx 'tools/rom_manifest_crystal.json' <<< "$archive_entries" \
+    || fail "game.love is missing the Crystal ROM import manifest"
   # This gate exists because the launcher's UI toolkit once lived outside
   # src/ (libs/flexlove) and was added to scripts/build.sh's payload and to
   # no other packager, so Android and iOS built an APK/IPA whose launcher