What I fixed:
Removed the warning-calculation N+1 queries. Occupancy warnings now use one floor-plan participant query instead of per-scene character/asset lookups.
Added SceneFloorPlanParticipant_ListByFloorPlan to the existing migration script with SET ANSI_NULLS ON and SET QUOTED_IDENTIFIER ON.
Reapplied the migration locally.
Confirmed FloorPlanBlock_Save, FloorPlan_GetEditor, and the new participant proc have quoted identifiers enabled.
Reduced drag/resize freeze risk by throttling expensive geometry recalculation to animation frames instead of every pointer event.
Added a final geometry refresh on pointer-up/cancel before autosave.
Improved autosave failure visibility by showing the real error in the editor, not just leaving status stuck.
Made Occupancy mode view/staging only:Blocks no longer start drag/resize in Occupancy mode.
Resize handles are hidden.
Structural toolbox is hidden.
Plan canvas expands to use the freed width.
Structure mode restores normal editing.
Verification:
dotnet build PlotLine.slnx passes with 0 warnings and 0 errors.
Non-destructive SQL smoke test of FloorPlanBlock_Save against the Lounge block passed inside a transaction and rolled back.
Confirmed the Lounge block stayed unchanged after the rollback.
Reapplied 081_FloorPlanFloorDescriptionAndOccupancyWarnings.sql successfully.
Files changed:
[Repositories.cs](C:/Source/PlotLine/PlotLine/Data/Repositories.cs)
[CoreModels.cs](C:/Source/PlotLine/PlotLine/Models/CoreModels.cs)
[CoreServices.cs](C:/Source/PlotLine/PlotLine/Services/CoreServices.cs)
[081 SQL migration](C:/Source/PlotLine/PlotLine/Sql/081_FloorPlanFloorDescriptionAndOccupancyWarnings.sql)
[Edit.cshtml](C:/Source/PlotLine/PlotLine/Views/FloorPlans/Edit.cshtml)
[site.css](C:/Source/PlotLine/PlotLine/wwwroot/css/site.css)
[site.min.css](C:/Source/PlotLine/PlotLine/wwwroot/css/site.min.css)
Manual browser QA still needed for the exact drag/add/reload flow, but the code path and SQL save path are now stabilized.
