docs: add bugs.md for tracking known visual/gameplay bugs

Start with BUG-001: wrong cloth textures on characters (observed
during rendering rebuild verification).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/bugs.md

@@ -0,0 +1,25 @@
+# acdream — known bugs
+
+Track visual, gameplay, and protocol bugs here. Close by moving to
+the "Fixed" section with the commit hash that resolved it.
+
+---
+
+## Open
+
+### BUG-001: Wrong cloth textures on characters
+- **Observed:** 2026-04-13
+- **Description:** Character clothing renders with incorrect textures.
+  ObjDesc Phase 5 (AnimPartChange + TextureChanges + SubPalettes) is
+  shipped but something is off — either a texture-swap ordering issue,
+  a missing remapping step, or a palette application bug.
+- **Repro:** Connect to ACE server, observe player character or NPCs.
+- **Likely area:** `WorldEntity` ObjDesc application, `TextureCache`,
+  or the CreaturePalette pipeline in `InstancedMeshRenderer`.
+- **Phase:** Unassigned (investigate after rendering rebuild Step 5).
+
+---
+
+## Fixed
+
+_(none yet)_