Add Changban refuge sortie chapter

docs/roadmap.md

@@ -40,15 +40,16 @@ Build a small complete tactical RPG loop that can grow into a longer Romance of
 - Seventeenth battle Wolong visit road, gated by Wolong clue visits, opening the Longzhong approach and recruiting Zhuge Liang into the roster after victory
 - Post-Wolong camp dialogue and visit events, including Zhuge Liang bond choices and Red Cliffs preparation clues
 - Eighteenth battle Bowang ambush as the first Red Cliffs preparation battle, with a new large battlefield, Xiahou Dun's vanguard, mixed enemy AI, Zhuge Liang sortie recommendation, and post-battle camp events
+- Nineteenth battle Changban refuge route, extending Red Cliffs preparation with a larger refugee-road battlefield, Cao Chun's cavalry pursuit, Zhao Yun survival pressure, and a sortie choice that highlights growing roster tradeoffs
 - Camp progress timeline tab that summarizes Liu Bei's long campaign arc, completed battles, current chapter, latest battle, and next major chapter
 - Tactical sortie preparation panel with battle-specific sortie limits, recommended officers with reasons, class role, named equipment, core stats, bond partner, next-map terrain suitability, deployment preview, formation roles, active bond count, recruited-officer count, reserve roster summary, and readiness advice for each deployable officer
 - Officer collection support in camp, including full roster status, selected/reserve/recommended markers, and post-battle reserve training growth for benched officers
 - Treasure equipment effects wired into battle previews and resolution, including named weapon damage bonuses, defensive treasure mitigation, support recovery bonuses, turn-start charm recovery, and equipment-specific growth bonuses
-- Flow verification script from title through the eighteenth battle victory, recruit sortie selection, Liu Biao visit rewards, Zhuge Liang recruitment, Bowang camp state, campaign timeline state, and camp save state
+- Flow verification script from title through the nineteenth battle victory, recruit sortie selection, Liu Biao visit rewards, Zhuge Liang recruitment, Bowang/Changban camp states, campaign timeline state, and camp save state
 
 ## Next Steps
 
-1. Continue the Red Cliffs preparation chapter into Changban and the Jiangdong envoy route
+1. Continue the Red Cliffs preparation chapter into the Jiangdong envoy route and the first Red Cliffs confrontation
 2. Add more recruitable officers as the campaign moves toward Red Cliffs, Jing Province, Yi Province, and Shu Han
 3. Expand reserve training into explicit drill choices, class practice, and bond-focused camp assignments
 4. Add a dedicated treasure/equipment management view so players can compare special effects and growth