make narrowing conversions in braced initialisers explicit

A braced initialiser does not allow a narrowing conversion unless the value
is a constant expression the compiler can prove fits. Every site here holds a
runtime value: WORLD_COLS is the global guiWorldCols, the laptop screen
coordinates are built from iScreenWidthOffset, the sector limits come from the
externalised options. MSVC accepts all of it silently; clang rejects it, and
it is ill-formed.

Nothing about the generated code changes. MSVC was already performing these
conversions; the casts only say so out loud, at the 73 places where it was
happening implicitly.

The invariant: each site is wrapped in a static_cast to the element type the
initialiser already had, and nothing else is touched. No type is widened, no
expression is reassociated, no value is clamped or checked. static_cast rather
than a C-style cast so that a later reader can grep for the narrowings, and so
that none of these can quietly become a reinterpret_cast if a type changes.

Verification:

    # every changed line differs only by inserted casts and their parentheses
    git show HEAD -U0 | grep '^[+-][^+-]' |
      sed -E 's/static_cast<[A-Za-z0-9_]+>//g; s/[()]//g; s/^[+-]//' |
      sort | uniq -c | awk '$1 % 2'          # no output

    git show HEAD -U0 | grep -c '^+[^+]'     # 38 lines, 73 casts

    ninja -C build parse                     # narrowing class gone: 129 -> 91 sites
    ninja -C build -k 0                      # Release, four applications, green
    ninja -C build-debug -k 0                # Debug, four applications, green

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

TileEngine/Isometric Utils.cpp

@@ -16,14 +16,14 @@ UINT32 guiForceRefreshMousePositionCalculation = 0;
 // GLOBALS
 INT16 DirIncrementer[8] =
 {
-		-WORLD_COLS,		//N
-		1-WORLD_COLS,		//NE
+		static_cast<INT16>(-WORLD_COLS),		//N
+		static_cast<INT16>(1-WORLD_COLS),		//NE
 		1,					//E
-		1+WORLD_COLS,		//SE
-		WORLD_COLS,			//S
-		WORLD_COLS-1,		//SW
+		static_cast<INT16>(1+WORLD_COLS),		//SE
+		static_cast<INT16>(WORLD_COLS),			//S
+		static_cast<INT16>(WORLD_COLS-1),		//SW
 		-1,					//W
-		-WORLD_COLS-1		//NW
+		static_cast<INT16>(-WORLD_COLS-1)		//NW
 };
 
 // Opposite directions