Add Hanzhong gate scenario

docs/ROADMAP.md

@@ -21,7 +21,7 @@
 - Destination victory conditions and objective map markers exist.
 - Turn-limit conditions and HUD turn-limit display exist.
 - Victory reward summary is visible.
-- Next-battle flow exists across the current thirty-nine-scenario campaign.
+- Next-battle flow exists across the current forty-scenario campaign.
 - Campaign completion and new-campaign reset exist.
 - Reward inventory can be brought into the next battle.
 
@@ -52,7 +52,7 @@
 - Party roster persistence has a first save-file skeleton.
 - Level, experience, and equipment persistence.
 - Chapter selection and save/load.
-- Linear thirty-nine-scenario campaign order exists.
+- Linear forty-scenario campaign order exists.
 - Save reset exists.
 - Victory rewards, consumable counts, equipment stock, and equipped gear persist.
 - A basic pre-battle shop with scenario-specific stock exists. Sell-back and richer item management are still planned.
@@ -99,6 +99,7 @@
 - Thirty-seventh-scenario content exists with Guanzhong foothold pressure, Ma Chao's rearguard, split-alliance tension, and 036 branch reactions.
 - Thirty-eighth-scenario content exists with Ma Chao retreat pressure, Guanzhong commandery stakes, western road pursuit, and 037 branch reactions.
 - Thirty-ninth-scenario content exists with Hanzhong approach pressure, Zhang Lu's border guard, mountain-gate stakes, and 038 branch reactions.
+- Fortieth-scenario content exists with Hanzhong gate pressure, Zhang Lu's mountain guard, pass-road siege stakes, 039 branch reactions, and submission or pacification follow-up flags.
 
 ## Milestone 5: Presentation