Fix marker crash on logout and add module lifecycle table

The marker cleanup hook on CleanupWorldAndEntities was never installed —
markers.installHooks() was missing from install() in main.zig. Entities
created via WorldMarker were never cleaned up before the game's atexit
handler iterated the hash table over freed heap memory.

Key changes:
- Add markers.installHooks() call (the actual crash fix)
- Replace manual install/uninstall/shutdown lists with a single modules
  table that drives all three phases — prevents this class of bug
- Gate marker Lua functions, addon, and keybindings behind isActive()
  so they're skipped when another DLL owns the hooks
- Add world_cleanup_hook.detach() to removeHooks() (was missing)
- Migrate from vendored libs/hook to external zhook dependency
- Unify installHooks return types to void across all modules
- Add diagnostic logging to marker cleanup (temporary, for testing)

src/outline/tracker.zig

@@ -11,7 +11,7 @@
 //! comparison against the object manager's validated set.
 
 const std = @import("std");
-const hook = @import("hook");
+const hook = @import("zhook");
 const wow = @import("wow.zig");
 const o = @import("offsets.zig");
 const types = @import("types.zig");