Consolidate shared game offsets and accessor functions

Extract duplicated WoW 1.12.1 addresses and game accessor functions
into shared modules (src/offsets.zig, src/wow.zig), replacing 5+
copies of getObjectByGUID, isInBattleground, isValidPtr, etc.

- src/offsets.zig: shared address constants (object manager, descriptor
  fields, map/zone, core function addresses, D3D9/GX)
- src/wow.zig: shared accessor functions (pointer validation, object
  manager traversal, field reads, unit helpers, battleground detection,
  game function wrappers, raid target cache)
- Update 10 modules to import from shared instead of inline constants
- Remove outline/wow.zig (promoted to src/wow.zig)
- Trim outline/offsets.zig and markers/offsets.zig to module-specific only

src/outline/tracker.zig

@@ -13,7 +13,7 @@
 const std = @import("std");
 const hook = @import("zhook");
 const logging = @import("../logging.zig");
-const wow = @import("wow.zig");
+const wow = @import("../wow.zig");
 const o = @import("offsets.zig");
 const types = @import("types.zig");