Chinese main menu: font atlas + GB2312 tables + Strings translation

- build_cjk.py: 2048x1024 UI atlas (original ASCII at 0,0 + full GB2312 at 12px) and
  cjk_glyph/cjk_metric tables.
- cn_strings.py + make_cn_strings.py: escape-aware GB2312 rewrite of Strings.dat (46 entries).
- install_cjk.py: one-shot deploy/restore (exe patch, atlas loose+res, strings).
- apply_cjk.py: fix metrics cave code byte order (was (second<<8)|first) so CJK width
  measures correctly and centred labels are no longer flushed right.
- docs: DEVLOG + patch notes for the atlas and the fix.

docs/patch-notes.md

@@ -64,17 +64,47 @@ Behaviour of each cave:
 Slot `0xFF` glyph lives at `font+0x100C`, its metric at `font+0x1814`; these do not collide with the
 real tables.
 
+## Byte-order detail (important)
+
+Both caves must build the code identically as `(first << 8) | second`:
+
+- draw cave: `movzx ecx,al; shl ecx,8; movzx eax,[edx+1]; or ecx,eax`
+- metrics cave: `movzx eax,al; shl eax,8; mov al,[ebx+1]`  (`al` is free after the `shl`)
+
+The metrics cave originally used `mov ah,[ebx+1]` which yields `(second<<8)|first`; CJK then
+measured as width 0 and centred labels were flushed right. Fixed.
+
+## Font atlas (implemented, `tools/build_cjk.py`)
+
+`AddChar` normalises rects by the **actual D3D texture size**, so replacing the UI font texture
+with a larger atlas that still contains the original ASCII art at pixel (0,0) keeps every existing
+`Fonts.dat` rect valid — no `Fonts.dat` edits needed.
+
+```
+Shrift_gb_Germany.TGA   2048 x 1024, 32bpp TGA (type 2, bottom-up, desc 0x08, 26-byte footer)
+  (0,0) 256x128   original ASCII/German artwork (byte-identical copy)
+  (0,128)+       12x12 cells, 170 per row, full GB2312 (7445 codes), simsun 12px, binary alpha
+```
+
+`cjk_glyph` holds normalised UVs `(x/2048, y/1024, (x+12)/2048, (y+12)/1024)`;
+`cjk_metric` holds `(12, 12)` (advance, height). Deployed as a loose file and inside
+`Textures.res` (see `tools/install_cjk.py`).
+
 ## Requirements / limits
 
-- The font texture must contain **both** ASCII and CJK glyphs (one texture per draw).
-  Plan: replace the UI font `Texture` with a 2048x2048 atlas and re-point the ASCII `Char` rects.
+- The font texture must contain **both** ASCII and CJK glyphs (one texture per draw); done via the
+  shared atlas above.
 - Lead bytes >= `0x80` are reserved for DBCS. ASCII is untouched.
-- Confirmed end to end: a GB2312-coded menu string rendered the mapped glyph on screen.
+- Only the `UI` font atlas is extended; the `OldUI` / `UISmall` / Russian fonts still point at their
+  own textures, so CJK drawn with those would need their own atlas/tables too.
 
 ## Tools
 
 - `tools/add_section.py` — append an executable PE section.
 - `tools/apply_cjk.py` — assemble the caves (keystone), add `.cjk`, write hooks and tables.
+- `tools/build_cjk.py` — build the atlas TGA + `cjk_glyph`/`cjk_metric` from a charset.
+- `tools/make_cn_strings.py` + `tools/cn_strings.py` — GB2312 translation of `Strings.dat`.
+- `tools/install_cjk.py` — deploy/restore everything into the game folder.
 - `tools/decode_dat.py` — decode/encode the XOR `.dat` files.
 - `tools/fontparse.py` — parse `Fonts.dat` into blocks + glyph rects.
 - `tools/xrefs.py`, `tools/disasm.py`, `tools/scan_disp.py` — RE helpers.