Expand vigor and tactical unit documentation (#8637)

docs/eagle0pedia/src/content/docs/battalions/index.md

@@ -20,7 +20,7 @@ These values do different jobs; they are not interchangeable ratings that simply
 - **Training** scales the battalion type's melee and missile damage bonuses. Higher training therefore means more damage per troop. It also affects some command-specific odds, including the chance to stun on a [Charge](/shardok-commands/#charge).
 - **Armament** scales the battalion type's resistances and reduces incoming normal damage. Each type and damage category has its own resistance profile, so the same ARM value does not protect every battalion equally. Penetrating damage bypasses this normal armament reduction. If the unit can use [Archery](/shardok-commands/#archery), armament also determines its starting volleys: currently one volley per 10 ARM, rounded down, plus any bonus from its battalion type.
 - **Morale** changes the battalion's damage swing. Most units also need at least 10 morale to use normal tactical commands.
-- **Hero vigor** is an action constraint and current energy reserve, not battalion armor. A hero-bearing unit normally needs at least 10 vigor to act, and special effects can spend or reduce it.
+- **Hero vigor** is an action constraint and current energy reserve, not battalion armor. It affects maximum AP and command access; at zero vigor, the hero-led unit is captured and removed from active battle. See [Vigor](/heroes/#vigor).
 - **Troop count** multiplies battalion damage: more surviving troops deliver more total battalion damage. It also determines how many soldiers remain available to absorb casualties.
 - **Battalion type** supplies the base damage, training bonus, resistance profile, armament benefit, movement costs, charge multiplier, and special capabilities.
 - **Hero stats** contribute separately. Charisma and bravery affect battalion combat swings, while a hero also contributes personal damage and enables stat- or profession-based commands.
@@ -55,7 +55,9 @@ An exceptional formation created through necromantic effects rather than ordinar
 
 ## Heroes and units
 
-A Shardok unit normally combines one hero and one battalion. The hero supplies stats, vigor, profession commands, and special capabilities; the battalion supplies troops, type, training, armament, movement, morale, and damage profile. A profession alone may not be enough: casting requires a casting-capable battalion, and Ranger stealth requires a stealth-capable one.
+A Shardok unit normally combines one hero and one battalion. The hero supplies stats, [vigor](/heroes/#vigor), profession commands, personal damage, and special capabilities; the battalion supplies troops, type, training, armament, movement, morale, and its damage profile. The hero's Charisma and Bravery also affect the battalion's combat swing. A profession alone may not be enough: casting requires a casting-capable battalion, and Ranger stealth requires a stealth-capable one.
+
+The two parts remain one tactical unit. If the battalion reaches zero troops, it is destroyed. If the attached hero reaches zero vigor, the hero-led unit is captured and removed from active battle; the surviving battalion does not detach and continue fighting independently.
 
 ## Creating and changing battalions
 

docs/eagle0pedia/src/content/docs/concepts/shardok-combat/index.md

@@ -17,7 +17,7 @@ Movement cost depends on terrain and battalion type. Water, mountains, bridges,
 
 Melee and ranged attacks require valid targets and battlefield geometry. Line of fire can be blocked. Damage and resistance depend on the units, heroes, damage profiles, and terrain involved.
 
-Many major actions require a minimum AP and then consume all remaining AP. The command reference states the exact rule. Unless an entry says otherwise, a morale-using unit needs at least 10 morale, and a unit with a hero needs at least 10 hero vigor.
+Many major actions require a minimum AP and then consume all remaining AP. The command reference states the exact rule. Unless an entry says otherwise, a morale-using unit needs at least 10 morale, and a unit with a hero needs at least 10 [hero vigor](/heroes/#vigor). Current vigor also contributes to maximum AP. Reaching zero vigor resolves the entire hero-led unit as captured, even if troops remain.
 
 ## Heroes and battalions
 

docs/eagle0pedia/src/content/docs/heroes/index.md

@@ -28,7 +28,37 @@ These values help drive hero flavor, AI decisions, and story generation.
 
 ## Vigor
 
-Vigor is a hero's current energy. Many commands require an acting hero and spend vigor. Resting restores vigor up to the hero's constitution.
+Vigor is a hero's current energy reserve. **Constitution is the hero's normal strategic vigor cap**; vigor and Constitution are related, but they are not the same stat.
+
+### Strategic vigor
+
+Many Eagle commands require an acting hero and spend vigor. The command reference lists each cost. A hero with too little vigor is not offered as an actor for that command.
+
+Vigor recovers over time and through deliberate recovery:
+
+- Each new month restores 5 vigor.
+- [Rest](/commands/#rest) restores up to 15 vigor to each faction hero in the province.
+- [Feast](/commands/#feast) restores up to 10 vigor to each faction hero in the province.
+- Recovery cannot raise strategic vigor above Constitution.
+
+Strategic actions that spend vigor also grant Constitution XP. Constitution can rise through normal stat advancement, increasing the hero's future strategic vigor cap.
+
+### Vigor in a Shardok battle
+
+A hero enters battle with the vigor they currently have after strategic costs such as marching. That value becomes the hero's **battle-start vigor** and the recovery ceiling for that battle. A tired hero can therefore enter with a battle recovery ceiling below their Constitution. The ceiling does not fall as the battle proceeds; current vigor falls and rises beneath it.
+
+Tactical vigor affects what a hero-led unit can do:
+
+- Higher current vigor contributes to the unit's maximum Action Points. A normal unit's maximum is 5 plus rounded `vigor / 25` plus rounded `morale / 25`.
+- Spending Action Points normally spends 0.5 vigor per AP, and some profession abilities have additional vigor costs.
+- Combat damage and battlefield effects can reduce vigor.
+- Ending an activation with unused AP, [Rest](/shardok-commands/#stop-or-rest), and effects such as [Holy Wave](/shardok-commands/#holy-wave) can restore vigor, but not above battle-start vigor.
+- Below 10 vigor, most ordinary tactical commands are unavailable. A few cleanup or required commands are exceptions.
+- At zero vigor, the hero-led unit is resolved as captured. Its surviving battalion does not remain on the map as an independently acting unit.
+
+While the hero remains active, their stats affect the battalion's combat swing, they add personal damage, and their profession can unlock special commands. Low vigor does not directly scale those contributions down point by point; it reduces AP and command access, with the decisive removal occurring at zero.
+
+When a tactical display shows `current / battle start`, the first number is current vigor and the second is the battle-start recovery ceiling—not Constitution. Enemy details may be hidden by battlefield knowledge. An absent or hidden enemy value must not be interpreted as an actual zero.
 
 ## Loyalty