feat(python): add TankOptions support to from_displacement

docs/source/api/python/hydrostatics.rst

@@ -1,7 +1,43 @@
 Hydrostatics
 ============
 
-Classes for hydrostatic calculations.
+
+TankOptions
+-----------
+
+.. py:class:: TankOptions(include_mass=False, include_fsm=True)
+
+   Options for tank handling in hydrostatic calculations.
+
+   :param include_mass: Include tank fluid mass in displacement (default: False)
+   :param include_fsm: Apply Free Surface Moment correction to GM (default: True)
+
+   .. py:staticmethod:: none()
+
+      Create options with no tank effects (mass=False, fsm=False).
+
+   .. py:staticmethod:: all()
+
+      Create options with all tank effects (mass=True, fsm=True).
+
+   .. py:staticmethod:: mass_only()
+
+      Create options with only mass included (mass=True, fsm=False).
+
+   .. py:staticmethod:: fsm_only()
+
+      Create options with only FSM correction (mass=False, fsm=True).
+
+   .. py:attribute:: include_mass
+      :type: bool
+
+      Whether tank mass is included.
+
+   .. py:attribute:: include_fsm
+      :type: bool
+
+      Whether FSM correction is applied.
+
 
 HydrostaticsCalculator
 ----------------------
@@ -13,7 +49,7 @@ HydrostaticsCalculator
    :param vessel: The vessel to calculate hydrostatics for
    :param water_density: Water density in kg/m³ (default: 1025.0 for seawater)
 
-   .. py:method:: from_draft(draft, trim=0.0, heel=0.0, vcg=None)
+   .. py:method:: from_draft(draft, trim=0.0, heel=0.0, vcg=None, num_stations=None, tank_options=None)
 
       Calculates hydrostatics at a given draft, trim, and heel.
 
@@ -22,9 +58,11 @@ HydrostaticsCalculator
       :param heel: Heel angle (degrees)
       :param vcg: Vertical center of gravity for GM calculation (optional)
       :type vcg: float or None
+      :param num_stations: Number of stations (optional)
+      :param tank_options: TankOptions object (optional)
       :returns: HydrostaticState with all properties
 
-   .. py:method:: from_drafts(draft_ap, draft_fp, heel=0.0, vcg=None)
+   .. py:method:: from_drafts(draft_ap, draft_fp, heel=0.0, vcg=None, tank_options=None)
 
       Calculates hydrostatics from drafts at Aft and Forward Perpendiculars.
 
@@ -33,9 +71,10 @@ HydrostaticsCalculator
       :param heel: Heel angle (degrees)
       :param vcg: Vertical center of gravity for GM calculation (optional)
       :type vcg: float or None
+      :param tank_options: TankOptions object (optional)
       :returns: HydrostaticState with all properties
 
-   .. py:method:: from_displacement(displacement_mass, vcg=None, cog=None, trim=None, heel=None)
+   .. py:method:: from_displacement(displacement_mass, vcg=None, cog=None, trim=None, heel=None, tank_options=None)
 
       Calculates hydrostatics for a given displacement, finding the required draft.
 
@@ -44,6 +83,7 @@ HydrostaticsCalculator
       :param cog: Full center of gravity (LCG, TCG, VCG) tuple (optional, overrides vcg)
       :param trim: Fixed trim angle in degrees (optional, default 0.0)
       :param heel: Fixed heel angle in degrees (optional, default 0.0)
+      :param tank_options: TankOptions object (optional)
       :returns: HydrostaticState with all properties