docs (en, pl) and editors: masks, tails, shuffles, lookup, dot_add, @cpu, cpu_has, Nix

- technicians' guides: section 31 rewritten around kernels (masks, the end of a list, moving lanes,
  int8 dot products, choosing instructions at build and at run time)
- cheat sheets and engineers' guides: the new operations and their IR; how features are found
- Kate and VS Code: @cpu, boolxN and the new built-ins highlighted

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Psc42moPLwP43Cmb9oZqSR

editors/vscode/syntaxes/finch.tmLanguage.json

@@ -147,11 +147,15 @@
           "match": "\\bself\\b"
         },
         {
-          "name": "storage.type.primitive.finch",
-          "match": "\\b(int|float|bool|char|str|ptr|map|i8|i16|i32|i64|u8|u16|u32|u64|f32|f64|[iuf](?:8|16|32|64)x(?:2|4|8|16|32|64))\\b"
+          "name": "storage.modifier.attribute.finch",
+          "match": "@cpu\\b"
         },
         {
-          "match": "\\b(print|input|read_file|write_file|file_exists|delete_file|shell|exit|addr|new|free|error|min|max|abs|clamp|assert|atomic_add|atomic_sub|atomic_load|atomic_store|atomic_swap|atomic_cas)\\s*(?=\\()",
+          "name": "storage.type.primitive.finch",
+          "match": "\\b(int|float|bool|char|str|ptr|map|i8|i16|i32|i64|u8|u16|u32|u64|f32|f64|(?:[iuf](?:8|16|32|64)|bool)x(?:2|4|8|16|32|64))\\b"
+        },
+        {
+          "match": "\\b(print|input|read_file|write_file|file_exists|delete_file|shell|exit|addr|new|free|error|min|max|abs|clamp|assert|atomic_add|atomic_sub|atomic_load|atomic_store|atomic_swap|atomic_cas|select|concat|fma|muladd|cpu_has|f32_bits|f32_from_bits|f64_bits|f64_from_bits|f16_to_f32|f32_to_f16|bf16_to_f32|f32_to_bf16)\\s*(?=\\()",
           "captures": {
             "1": {
               "name": "support.function.builtin.finch"