Open Route 42 to Mahogany, the Lake of Rage, the Rocket Hideout and Pryce (#32)

Route 42, Mt. Mortar, Mahogany Town, Route 43 and its gates, the Lake of
Rage and its houses, the Rocket Hideout and Route 44 are open. The story
plays through the toll, the red Gyarados, Lance, the hideout and Pryce's
GLACIERBADGE, which starts the Radio Tower takeover.

The fishing guru measures Magikarp (CheckMagikarpLength,
MagikarpHouseSign, FindPartyMonThatSpecies); the record is saved.
takemoney now leaves a short account at zero as TakeMoney does, and
setmapscene/setscene on a map without scenes consume the byte instead of
refusing. The playthrough's path search slides on ice and the run gains
five stages to Pryce.

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

docs/PLAN.md

@@ -18,6 +18,8 @@ The emulator-backed prototype is now at `/reference.html`. The default applicati
 | Route 31, Violet City, Sprout Tower and Falkner's gym                        | Done (Dark Cave: Violet entrance only)  |
 | Goldenrod City, Whitney and local shops and gifts                          | Done                                    |
 | Routes 35–37, the National Park, Ecruteak and Morty                          | Done (Tin Tower closed)                 |
+| Routes 38–41, Olivine, Cianwood, Chuck and Jasmine                           | Done (port, Battle Tower closed)        |
+| Route 42 to Mahogany, the Lake of Rage, the Rocket Hideout and Pryce          | Done                                    |
 | Wild and trainer battles, capture and the catching tutorial                  | Done for the areas that are open        |
 | 1. Complete the overworld foundation                                         | Done                                    |
 | 2. Opening story and first battle slice                                      | Mostly done                             |
@@ -419,6 +421,15 @@ The numbered sections below keep their full scope. Each one opens with a checkli
 - Local validation (2026-10-13): 790 unit tests passed, 3 skipped (scratch tests excluded), including the 32-stage playthrough; without a ROM, 168 passed and 625 skipped. Both builds, reference/profile checks, vendor integrity and release isolation passed. Browser checks: 181 passed, 21 skipped, 12 known WebKit menu failures (#70). CI and physical-device acceptance were not run.
 - Remaining: Olivine's port and the S.S. Aqua, the Battle Tower, Whirl Islands, the Game Boy Printer, routes beyond Olivine and Cianwood (Route 42 onward), radio and rematches (#30), breeding (#29), mobile and link features, and audio.
 
+## Implemented: Route 42 to Mahogany, the Lake of Rage, the Rocket Hideout and Pryce (board #32, increment E)
+
+- Route 42 with its Ecruteak gate, Mt. Mortar's four maps, Mahogany Town with its Pokémon Center, gym, souvenir shop and the red Gyarados speech house, Route 43 with both gates, the Lake of Rage with the Hidden Power and fishing guru houses, the Rocket Hideout's three floors and Route 44 are open. Ice Path and the Radio Tower takeover follow.
+- The story runs on existing primitives: the Rockets' toll at the Route 43 gate (charged on every pass until the hideout is cleared), the red Gyarados (forced shiny) and the Red Scale, Lance, Dragonite's Hyper Beam on the souvenir shop's stairs, the hideout's cameras and exploding traps, Lance's healing, the two door passwords, the rival, both executives, the Murkrow's password, the six Electrodes and HM06, Pryce's ice floor, the GLACIERBADGE and TM16, and `RadioTowerRocketsScript` at seven badges.
+- New specials: `CheckMagikarpLength`, `MagikarpHouseSign` and `FindPartyMonThatSpecies` (`game/scripts/lake-of-rage.ts`). The Magikarp record and holder are saved as `magikarpRecord` (3′6″ by RALPH in a new game, and in older saves).
+- Engine fixes: `takemoney` leaves a short account at zero, as `TakeMoney` does (it used to leave it unchanged). `setmapscene` and `setscene` on a map without a scene variable consume the scene byte instead of refusing; see NATIVE_PORT.md for where the original writes it.
+- The playthrough driver's path search slides on ice. Tests: `tests/mahogany.test.ts` covers the record, its holder and reload, every guru answer, an Egg, the Elixer on standby and the toll. The playthrough continues for five more stages, from Olivine to Pryce.
+- Remaining: the Radio Tower takeover, Ice Path, Blackthorn, Clair, Dragon's Den, Routes 45 and 46, Tin Tower, Whirl Islands, radio and rematches (#30), breeding (#29), mobile and link features, and audio.
+
 ## Native battles: current state
 
 The battle core, ROM tables, encounter hooks, battle UI and whiteout hooks are present. Unit tests cover wins, escape, loss, experience, move learning and capture; reference tests compare damage, type effectiveness, stat calculation and experience curves. Browser tests drive a test-only wild encounter through the real UI: victory with level-up and move learning, escape, whiteout, catching with a nickname, keyboard and on-screen D-pad menu navigation, mid-battle backup restore, rollback of unsupported effects, switching through the party menu and a Potion from the Items pocket. Real Route 29 encounters now use the ROM's encounter tables. Every ball can be thrown; only the contest's Park Ball handling remains.