depend on factory data instead of BuildingSystem in the AI path

Ten queries that read nothing but FactoryState become free functions in
FactoryQueries.h; the BuildingSystem methods stay as one-line forwards, so no
existing caller moves yet.

That lets the AI path drop its dependency on the system entirely. AiSystem,
SalvagerSystem, DeliverScrapEvaluator and DeliverScrapExecutor took a
BuildingSystem& purely to call findBuilding, findNearestBuilding and
deliverScrapToSalvageBay — all three are state-pure — so they now take
FactoryState& and say what they actually read. Four forward declarations of
BuildingSystem go with them.

No facade: the queries are plain free functions over the data. A facade was
considered to spare the ~180 UI call sites, but the AI needed only the data and
would have been given GameConfig it has no use for.

isProductionBuildingType moves to BuildingType.h beside isAutoRecipeBuildingType
and isBeltSubsystemType rather than being copied into the new file.

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/FactoryQueries.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include <vector>
+
+#include <QPoint>
+#include <QVector2D>
+
+#include "Building.h"
+#include "BuildingId.h"
+#include "BuildingType.h"
+#include "FactoryState.h"
+
+// Queries and operations over the factory's world data that need nothing but that
+// data — no config, no belts, no RNG. Free functions rather than BuildingSystem
+// methods so that callers depend on the data they read instead of on the system
+// that happens to tick it (see FactoryState.h).
+//
+// A helper belongs here only if it is a pure function of FactoryState. Anything
+// needing GameConfig or the asteroid bound stays on BuildingSystem for now.
+
+// The building with the given id, or nullptr when no building has it. Construction
+// sites are not buildings yet — use findSite for those.
+const Building* findBuilding(const FactoryState& state, BuildingId id);
+Building*       findBuilding(FactoryState& state, BuildingId id);
+
+// The queued construction site with the given id, or nullptr.
+const ConstructionSite* findSite(const FactoryState& state, BuildingId id);
+
+std::vector<Building>         getAllBuildings(const FactoryState& state);
+std::vector<ConstructionSite> getAllSites(const FactoryState& state);
+
+// REQ-UI-DEBUG-OVERLAY "Max Factory Production": count of completed
+// (operational) Miner/Smelter/Assembler/ReprocessingPlant/Shipyard buildings.
+int getProductionBuildingCount(const FactoryState& state);
+
+// REQ-UI-DEBUG-OVERLAY "Current Factory Production": subset of the above that
+// currently has an active production cycle.
+int getActiveProductionBuildingCount(const FactoryState& state);
+
+bool isTileOccupied(const FactoryState& state, QPoint tile);
+
+// The nearest building of the given type to a world position, or nullptr when
+// none exists. Distance is measured to the building's footprint centre.
+const Building* findNearestBuilding(const FactoryState& state, QVector2D worldPos,
+                                    BuildingType type);
+
+// Hands one scrap to a Salvage Bay's output buffer (REQ-BLD-SALVAGE-BAY). Fails
+// if the id is not a Salvage Bay, it is queued for deconstruction
+// (REQ-BLD-DECON-QUEUE), or its holding capacity is already taken — emerging
+// scrap counts against that capacity (REQ-MAT-OUTPUT-EMERGE).
+bool deliverScrapToSalvageBay(FactoryState& state, BuildingId bayId);