Document carry capacity placeholder

Docs/InventoryDataModel.md

@@ -120,6 +120,27 @@ The 0.1.E inventory work should implement these operations on top of the model:
   systems layered on top.
 - UI: read the replicated stack list and send requests back through server RPCs.
 
+## Carry Capacity Placeholder
+
+The 0.1.E MVP carry-capacity placeholder is implemented as a weight-first
+movement penalty, not a hard inventory lock. Each `FAgrarianItemStack` stores
+`UnitWeight`; `UAgrarianInventoryComponent::GetTotalWeight` sums
+`Quantity * UnitWeight`; and `AAgrarianGameCharacter` reads that total through
+`GetCurrentCarryWeight`.
+
+The default comfort and heavy thresholds are `25.0` and `60.0` item-weight
+units. `StrengthMultiplier` scales those thresholds so stronger characters can
+carry more before penalties. Movement remains full speed at or below the
+effective comfort threshold, trends down toward `65%` between comfort and heavy
+loads, and uses a `45%` carry multiplier at or above the heavy threshold. The
+debug HUD shows current carried weight so designers can tune item weights during
+play tests.
+
+This intentionally leaves volume, containers, backpacks, injuries, fatigue,
+awkward-object handling, and hard over-encumbrance rules for later systems.
+Those systems should build on the existing total-weight hook instead of adding a
+parallel inventory burden model.
+
 ## Equipment Slot Decision
 
 Dedicated equipment slots are deferred for the 0.1.E MVP. Current MVP tools,

Docs/TechnicalDesignDocument.md

@@ -130,6 +130,14 @@ or mesh-attachment state. When that need appears, equipment should be added as
 server-authoritative, replicated, persisted slot state rather than as local UI
 selection only.
 
+Carry capacity is active as an MVP placeholder through stack `UnitWeight`,
+inventory `GetTotalWeight`, and character movement penalties. The current
+character uses `25.0` comfort and `60.0` heavy item-weight thresholds, scales
+those thresholds by strength, and exposes current carried weight in the debug
+HUD. Future backpacks, containers, awkward-object rules, and hard overload
+limits should extend this total-weight path rather than creating a second carry
+model.
+
 ## Time And Environment
 
 The MVP gameplay calendar target is: