migrate every factory query off BuildingSystem onto the free functions

The eleven forwarding members added last commit are gone; callers now read the
data directly through FactoryQueries.h. Simulation and ArenaSimulation expose
getFactoryState() so the UI, the balancing view and the tests can reach it.

isQueuedForDeconstruction joined the free functions along the way — it only
reaches findBuilding, so it was state-pure too.

No facade was introduced. The chained form was the reason one looked attractive,
but rewriting sim.getBuildings().findBuilding(id) to findBuilding(sim.getFactoryState(), id)
turned out to be mechanical, and the result says which data is read rather than
which system happens to own it.

BuildingSystem.cpp is down to 1735 lines and no longer answers questions about
the factory — it only changes it. What remains on it are the mutators, the tick
phases, and the queries that also need GameConfig.

Verified with a golden-checksum capture before and after — all four sample ticks
identical.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YHcUerKAZKWNvSKJxYKbnG

src/lib/sim/BuildingSystem.h

@@ -94,7 +94,6 @@ public:
     void cancelDeconstruction(BuildingId id);
 
     // True if the building is currently in the deconstruction queue.
-    bool isQueuedForDeconstruction(BuildingId id) const;
 
     // Set the recipe (or schematic id for shipyard) on a building or queued
     // construction site.  Clears both buffers on an operational building.
@@ -140,18 +139,12 @@ public:
         Rotation     directionB; // Splitter: second output; Belt: same as directionA
     };
 
-    const Building*           findBuilding(BuildingId id)  const;
-    const ConstructionSite*   findSite(BuildingId id)      const;
-    std::vector<Building>     getAllBuildings()             const;
-    std::vector<ConstructionSite> getAllSites()             const;
 
     // REQ-UI-DEBUG-OVERLAY "Max Factory Production": count of completed
     // (operational) Miner/Smelter/Assembler/ReprocessingPlant/Shipyard buildings.
-    int getProductionBuildingCount() const;
 
     // REQ-UI-DEBUG-OVERLAY "Current Factory Production": subset of the above
     // that currently has an active production cycle.
-    int getActiveProductionBuildingCount() const;
 
     // Production state for the UI status light (REQ-UI-STATUS-LIGHT). Returns
     // nullopt for building types that show no light (belts, splitters, tunnels,
@@ -201,7 +194,6 @@ public:
 
     // Place one "scrap" item into a SalvageBay's output buffer.
     // Returns false if bay not found, wrong type, or output buffer is full.
-    bool deliverScrapToSalvageBay(BuildingId bayId);
 
     // Bypass the construction queue and create a fully-operational Building
     // immediately. Used for pre-placed structures (HQ, defence stations).
@@ -234,7 +226,6 @@ private:
                                             const std::vector<ItemType>& splitterFilterA,
                                             const std::vector<ItemType>& splitterFilterB);
 
-    Building*            findBuildingMutable(BuildingId id);
     // True if the consumer would accept `type` at the given input port right now:
     // it is a required input (or a building block for the HQ), the reservation-aware
     // buffer has room, and the input belt entry is free (REQ-MAT-INPUT-INTAKE).