Select Color: Document and Color books tabs

Document tab: every concrete colour the drawing uses (objects, block
definitions and layers), found in one pass when the panel opens, as a
grid of swatches sortable by recently used, most used, colour and colour
number. The recently-used list is now kept per drawing, so the ribbon's
Recent row shows this drawing's colours.

Color books tab: load AutoCAD .acb colour books (remembered in the
settings on desktop), browse them page by page with the page strip,
search by name and see the RGB equivalent. A book colour is applied as
RGB plus its BOOK$NAME identity on objects and layers instead of
dropping the name.

Strings translated into all 22 locales.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013rGmDUNr1hUf4zo1X3dak8

locales/en-US/opencadstudio.ftl

@@ -1344,6 +1344,21 @@ common =
     .color-hex = Hex
     .nearest-index-color = Nearest index
     .exact-index-match = Exact index match
+    .color-recently-used = Recently used
+    .color-most-used = Most used
+    .color-number = Color number
+    .color-in-drawing = Colors in this drawing
+    .color-sort = Sort
+    .color-no-drawing-colors = No colors in this drawing yet
+    .color-books = Color Books
+    .color-no-books = No color books loaded
+    .color-load-book = Load color book (.acb)
+    .color-book-label = Color book
+    .color-rgb-equivalent = RGB equivalent
+    .color-no-match = No colors match
+    .color-not-a-book = Not a color book
+    .color-book-encrypted = This color book is encrypted and cannot be read
+    .color-book-empty = The color book has no colors
     .cad-color-index-aci-10-249 = CAD Color Index (ACI) 10–249
     .grayscale-250-255 = Grayscale 250–255
     .isometric-drafting = Isometric drafting