docs: finish conservative non-TP3 corpus cleanup

The first pass matched keywords case-sensitively and left uppercase UNIT/USES
sources.  Match keywords case-insensitively, remove the remaining 26 marked
sources and 13 all-marked archives, and record the final 80-file/44-compiling
corpus.

CORPUS-TEST.md

@@ -68,16 +68,16 @@ The obvious non-TP3 material was removed:
 
 - the whole `Dezip/swag-pascal-master` tree and its
   `swag-pascal-master.zip`;
-- 390 `.pas` files outside that tree that declare `unit`, use `uses`, or carry
+- 416 `.pas` files outside that tree that declare `unit`, use `uses`, or carry
   FreePascal/Delphi markers;
-- 29 zip archives whose Pascal entries were **all** marked in that way.
+- 42 zip archives whose Pascal entries were **all** marked in that way.
 
 Mixed archives — including `pascsrc.zip`, which also contains the 44 compiling
 TP3 examples — were deliberately kept.
 
 Before cleanup: **6,810 files**, **4,919 `.pas`**, **907 zips**.
-After cleanup: **1,779 files**, **106 `.pas`**, **871 zips**.
+After cleanup: **1,740 files**, **80 `.pas`**, **858 zips**.
 
-The remaining 106 Pascal files compile as **44 OK / 62 errors**; the errors are
+The remaining 80 Pascal files compile as **44 OK / 36 errors**; the errors are
 TP3-feature gaps such as `Word`, `LongInt`, `absolute`, `Printer`/`Dos`, and the
 missing include files, not the unit/Delphi noise.