refactor(lang): rename the ptr/ptrs types to pointer/pointers

Expand the abbreviated pointer types to full words on the language surface:
  ptr   ->  pointer     (a raw address / FFI handle)
  ptrs  ->  pointers    (a buffer of pointers)

The Ludic type name is distinct from LLVM's own `ptr` spelling: llty() maps
`pointer`/`pointers` to LLVM `ptr`, and the emitted IR keeps `ptr`, so only
the Ludic-level surface changes. Rewrites type annotations across all
sources, the 8 hardcoded pointer type-tags, the `pointers`-buffer indexing
in emit_addr, the grammars/LSP/JetBrains tokens, and the docs
(type-ptr -> type-pointer, type-ptrs -> type-pointers). int/bool keep their
conventional short spelling (like Math).

Reseeded; C-free fixpoint holds; all suites green (45/24/29); site + check.py OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/language/memory/memory-bytes.md

@@ -4,7 +4,7 @@ name: Memory.bytes
 category: memory
 kind: namespace-method
 tokens: Memory.bytes
-sig: Memory.bytes(n) -> ptr
+sig: Memory.bytes(n) -> pointer
 tip: Allocate n bytes.
 order: 0
 ns: Memory