Port the start menu, the party menu and the pack outside battle

Start opens the original start menu. POKéMON shows the party with the
Pokémon submenu (stats, switching, move order, held items); PACK shows the
four pockets with the field item effects for healing, PP and the Bicycle,
plus giving and tossing. The menu runs on a script draft, and its cursors
persist until a battle clears them. Select keeps the Key Items shortcut.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/SESSION_HANDOFF.md

@@ -1,6 +1,6 @@
 # Recovered Claude session
 
-Latest continuation: see **Controlled capture comparisons: 2026-09-30**
+Latest continuation: see **Start menu, party menu and pack: 2026-09-30**
 at the end of this file. Earlier sections are historical snapshots.
 
 Recovered on 2026-09-23 from the local Claude Code transcript
@@ -688,3 +688,44 @@ verified. This handoff-only follow-up records that delivery.
 
 Next: party and bag menus outside battle, MOVE PKMN W/O MAIL and evolution.
 PLAN section 2 is complete within its recorded acceptance boundaries.
+
+
+## Start menu, party menu and pack: 2026-09-30
+
+Resumed from `60e06ae` (clean tree) with "continue" from the handoff: the
+next plan items were the party and bag menus outside battle, then
+evolution.
+
+- `src/game/scripts/start-menu.ts` (`StartMenuRun`): Start opens the
+  original start menu (items and descriptions from `StartMenu.Items`, list
+  from `SetUpMenuItems`). POKéMON: party menu (`PartyMenuStrings`), the
+  submenu from `MonMenuOptions` (field moves first), STATS, SWITCH,
+  MOVE (swap moves with PP), ITEM (GIVE from the pack with swap and
+  pack-full refund, TAKE). PACK: four pockets with left/right, the item
+  submenus from `MenuHeader_*.MenuData` by permissions and field menu,
+  TOSS with quantity and confirmation, GIVE, and USE through `ItemEffects`
+  addresses: HP items, status healers, Full Restore, revives, bitter
+  herbs, Ethers/Elixers/MysteryBerry and PP Up (one step, because
+  `wUsePPUp` aliases `wTempPP`), and the Bicycle (queued script after the
+  menu closes; Oak's warning where it cannot be used).
+- It runs on a script draft; saves while open keep the prior state. Menu
+  cursors persist in memory and reset after battle (`CleanUpBattleRAM`);
+  the party cursor now reaches the battle's `ChangeHappiness` quirk.
+- Select keeps the Key Items shortcut (browser tests moved from Enter to
+  Shift). New `pack` script effect/choice; `MENU` profile table checked by
+  `check:reference`; menu, pocket and PP constants moved into the verified
+  `C` block; `ENGINE_POKEGEAR` added and verified. The text decoder gained
+  `<POKE>` ($24), needed for "POKéGEAR".
+- Notices without changes: POKéDEX, POKéGEAR, trainer card, OPTION, field
+  moves from the menu, MAIL (giving or reading), SEL, evolution stones,
+  Rare Candy, vitamins and other field items.
+
+Checks: 353 unit tests with the local ROM (16 new in
+`tests/start-menu.test.ts`); 109 Chromium/WebKit browser tests passed, 19
+skipped intentionally (one new start-menu flow in both browsers); native
+and reference builds, reference, vendor and release checks; `git diff
+--check`. No emulator comparison of the menus; no CI or physical-device run.
+
+Next: evolution (`EvolveAfterBattle` after battles and from stones/Rare
+Candy, with the level-up flags the battle must record), then vitamins,
+MOVE PKMN W/O MAIL, SEL/registered items and field moves from the menu.