implement blueprint compatible overlap and configuration transfer

Implements the two rules specified in 128bf81, which restore the
copy-settings capability removed in 648241b as a property of blueprint
placement: press C on one configured building, then click same-type
buildings to stamp its settings across the factory.

The ghost colour and the click path already shared one predicate,
canPlaceBuilding, which is what kept preview and outcome from disagreeing.
The new rules make that answer four-valued, so the shared predicate becomes
a shared classifier: resolveBlueprintGhost in PlacementRules returns
PlaceNew / CompatibleOverlap / Transfer / Invalid, and both callers switch
on it. Putting it in lib rather than in the view is the whole testability
story -- src/ui is off the test include path.

findRotateInPlaceTarget is now the tunnel guard plus a shared
findCoincidingSameTypeBuilding core, so the two rules cannot drift apart;
its existing tests pass untouched. Blueprint placement no longer emits
RotateInPlaceCommand at all. Builder mode and the belt drag are unchanged.

transferConfigTo sends every field unconditionally, so a field the
blueprint stores nothing for clears the target's rather than leaving it.
The simulation's unchanged-value guards absorb the no-op case, which is
what keeps clicking an already-matching building free of buffer and
production-progress loss.

drawBuildingGhost's bool valid becomes GhostTint{Normal,Invalid,Transfer};
the transfer colour is taken at full RGB like the invalid one so it does
not double-dim against the ghost opacity. visuals.toml regains the overlay
colour under the name config_transfer, with its VisualsConfig field and
loader line -- overlay keys are mandatory, so the three move together.

The six new resolveBlueprintGhost cases failed on first run because the
test buildings were anchored in space: BuildingSystem::place skips the
terrain rules, resolveBlueprintGhost applies them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JcReq7hVk4KUPhTDKWAG7K

bin/app/data/config/visuals.toml

@@ -348,6 +348,7 @@ deconstruct_tint  = "#ff000033"   # deconstruct-mode hover tint
 selection_rect = "#00ff00"     # box-drag selection rectangle (REQ-UI-MULTI-SELECT)
 tile_highlight = "#ffffff22"   # tile under cursor
 selected_outline = "#ffff00"   # outline drawn around currently-selected building(s)
+config_transfer = "#33ccff66"  # blueprint ghost over a configuration-transfer target (REQ-UI-BLUEPRINT-TRANSFER)
 locked_asteroid = "#0000007f"  # tint over the asteroid left of the buildable edge (not yet unlocked by expansion)
 modal_dim      = "#00000099"   # semi-transparent black dim behind modal dialogs/menus (REQ-UI-MODAL-DIM)
 tunnel_preview = "#00ff0055"   # tunnel connection preview: matched end + tiles between (REQ-BLD-TUNNEL-MODE)