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.

docs/mod-api-gen2-compat.md

@@ -55,10 +55,10 @@ The short version, for an author deciding what to write:
 ```
 
 `games` is an optional array of version ids (`"red"`, `"blue"`, `"yellow"`,
-`"gold"`, `"silver"`), generations (`"gen1"`, `"gen2"`, case-insensitive) or
-`"all"`. `src/mods/ModTargets.lua` resolves the tokens off `GameVersion.ORDER`
-and `GameVersion.generation`, so nothing anywhere restates the game list.
-`"gen2"` now expands to both Gold and Silver.
+`"gold"`, `"silver"`, `"crystal"`), generations (`"gen1"`, `"gen2"`,
+case-insensitive) or `"all"`. `src/mods/ModTargets.lua` resolves the tokens off
+`GameVersion.ORDER` and `GameVersion.generation`, so nothing anywhere restates
+the game list. `"gen2"` now expands to Gold, Silver and Crystal.
 `Manifest.validate` stores the resolved, ORDER-sorted ids on `manifest.games`
 and **derives** `manifest.gen2compat` from them, which is the one field the
 loader's gate reads.

docs/new-features.md

@@ -19,5 +19,6 @@ Features intentionally added beyond the original Pokémon Red, Blue, and Yellow
 ## Gen 2 Specifics
 
 * **Pokémon Silver** as an importable, launcher-selectable version alongside Gold
+* **Pokémon Crystal** as an importable, launcher-selectable version alongside Gold and Silver
 * **Mod manager** with Gen 1 mod adapters, per-game targeting, and `modkit gen2check`
 * **Followers** for mods, plus Gen 2-only registries and hooks

docs/preparing-your-mod-for-gen2.md

@@ -176,7 +176,7 @@ something the filesystem encodes.
 
 | token | means |
 | --- | --- |
-| `"red"`, `"blue"`, `"yellow"`, `"gold"`, `"silver"` | that one game (a version id from `GameVersion.ORDER`) |
+| `"red"`, `"blue"`, `"yellow"`, `"gold"`, `"silver"`, `"crystal"` | that one game (a version id from `GameVersion.ORDER`) |
 | `"gen1"`, `"gen2"` | every game of that generation (case-insensitive; `"gen 2"` also parses) |
 | `"all"` | every game this engine has |
 

docs/switch-transfer.md

@@ -22,8 +22,8 @@ Player install (what to download, title override) stays in
 | Loose iteration pair | `sdmc:/switch/gen1recomp/gen1recomp.nro` **and** `game.love` beside it |
 | ROM inbox | LÖVE save dir → `imports/` (launcher shows the live `getSaveDirectory()` path; under MTP often `1: SD Card/<save identity>/imports/`) |
 | Mod zip inbox | Same save dir → `imports/mods/` then MODS → **Scan again** |
-| Save `.sav` inbox | Same save dir → `imports/saves/red\|blue\|yellow\|gold\|silver/` then that game's SAVE FILES → **Import save** (Gold / Silver cart `.sav` not supported yet) |
-| Save exports | Same save dir → `exports/red\|blue\|yellow\|gold\|silver/` (pull after **Export save**; Gold / Silver cart `.sav` not supported yet) |
+| Save `.sav` inbox | Same save dir → `imports/saves/red\|blue\|yellow\|gold\|silver\|crystal/` then that game's SAVE FILES → **Import save** (Gen 2 cart `.sav` not supported yet, on Gold, Silver or Crystal) |
+| Save exports | Same save dir → `exports/red\|blue\|yellow\|gold\|silver\|crystal/` (pull after **Export save**; Gen 2 cart `.sav` not supported yet, on Gold, Silver or Crystal) |
 | Opt-in diagnostics | Empty `switch-debug.txt` in the save dir → `switch.log` |
 | Lua error log | `lua-error.log` in the save dir |
 
@@ -54,8 +54,8 @@ macOS, not a Mac-only requirement.
 3. Create `switch/gen1recomp/` if needed; extract the release zip at SD root
    (or copy NRO / `game.love` for loose).
 4. For ROMs/mods/saves, open the save-dir `imports/`, `imports/mods/`,
-   `imports/saves/<red|blue|yellow|gold|silver>/`, or
-   `exports/<red|blue|yellow|gold|silver>/`
+   `imports/saves/<red|blue|yellow|gold|silver|crystal>/`, or
+   `exports/<red|blue|yellow|gold|silver|crystal>/`
    path the launcher prints.
 5. Wait for the queue; refresh; exit MTP responder; title-override launch.