refactor(stdlib): de-abbreviate namespaces (Mem/Sys/Net/Collide)

Expand the abbreviated public namespaces to full words, part of the
language-wide de-abbreviation pass:
  Mem -> Memory, Sys -> System, Net -> Network, Collide -> Collision

Math stays (universally accepted, like int/bool). Renames the dispatch
strings, LSP signatures, docs (dirs, files, frontmatter), and the
inventory manifest; behavior is byte-identical (the bare rt_ targets are
unchanged). Reseeded; C-free bootstrap fixpoint holds; all suites green.

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

docs/language/memory/_section.md

@@ -0,0 +1,7 @@
+---
+id: memory
+title: Memory
+order: 6
+---
+
+Raw memory — allocate byte and word buffers, copy and fill regions, and peek/poke individual bytes. The low-level escape hatch.

docs/language/memory/memory-bytes.md

@@ -0,0 +1,14 @@
+---
+id: memory-bytes
+name: Memory.bytes
+category: memory
+kind: namespace-method
+tokens: Memory.bytes
+sig: Memory.bytes(n) -> ptr
+tip: Allocate n bytes.
+order: 0
+ns: Memory
+member: bytes
+---
+
+Allocates an <code>n</code>-byte buffer and returns a pointer to it.

docs/language/memory/memory-copy.md

@@ -0,0 +1,14 @@
+---
+id: memory-copy
+name: Memory.copy
+category: memory
+kind: namespace-method
+tokens: Memory.copy
+sig: Memory.copy(dst, src, n) -> void
+tip: Copy n bytes between buffers.
+order: 2
+ns: Memory
+member: copy
+---
+
+Copies <code>n</code> bytes from <code>src</code> to <code>dst</code> (regions must not overlap).

docs/language/memory/memory-fill.md

@@ -0,0 +1,14 @@
+---
+id: memory-fill
+name: Memory.fill
+category: memory
+kind: namespace-method
+tokens: Memory.fill
+sig: Memory.fill(buf, value, n) -> void
+tip: Set n bytes to a value.
+order: 3
+ns: Memory
+member: fill
+---
+
+Sets the first <code>n</code> bytes of <code>buf</code> to the byte <code>value</code>.

docs/language/memory/memory-peek.md

@@ -0,0 +1,14 @@
+---
+id: memory-peek
+name: Memory.peek
+category: memory
+kind: namespace-method
+tokens: Memory.peek
+sig: Memory.peek(buf, i) -> int
+tip: Read one byte.
+order: 4
+ns: Memory
+member: peek
+---
+
+Returns the byte at <code>buf[i]</code> as an int in 0..255.

docs/language/memory/memory-poke.md

@@ -0,0 +1,14 @@
+---
+id: memory-poke
+name: Memory.poke
+category: memory
+kind: namespace-method
+tokens: Memory.poke
+sig: Memory.poke(buf, i, value) -> void
+tip: Write one byte.
+order: 5
+ns: Memory
+member: poke
+---
+
+Stores the low byte of <code>value</code> at <code>buf[i]</code>.

docs/language/memory/memory-words.md

@@ -0,0 +1,14 @@
+---
+id: memory-words
+name: Memory.words
+category: memory
+kind: namespace-method
+tokens: Memory.words
+sig: Memory.words(n) -> words
+tip: Allocate n 32-bit words.
+order: 1
+ns: Memory
+member: words
+---
+
+Allocates a buffer of <code>n</code> 32-bit integer words, indexable as <code>w[i]</code>.