feat(types): Dict + Set string-keyed containers (#54)

Types phase 4 — containers. A splice-on-demand open-addressing hash table
(runtime/native/dict.ludic, FNV-1a, linear probing, tombstones, grow at 0.7)
behind two namespaces:

- Dict.* — string -> int map: new/set/get/get_or/has/remove/size/clear/keys.
  Resource counts, id/name registries. O(1) average vs a linear list scan.
- Set.* — set of strings: new/add/has/remove/size/clear/members. Tags,
  unlocked achievements, visited tiles. Shares the same table.

Values are int (also an entity handle / small id); Value.* covers richer
maps. [T; N] inline fixed arrays remain future work — typed buffers and []T
slices already cover heap-backed arrays.

Wired: parser splice trigger (g_uses_dict), emit_call dispatch, reseeded seed,
a self-asserting example (examples/library/containers.ludic + feat_case), and
per-symbol docs + inventory. All suites green incl. golden renders byte-
identical and the bootstrap fixpoint.

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

docs/language/set/_section.md

@@ -0,0 +1,7 @@
+---
+id: set
+title: Set
+order: 13
+---
+
+A set of string members — membership tests for tags, unlocked achievements, or visited tiles. A <code>Set</code> shares the same open-addressing hash table as <code>Dict</code>, so <code>add</code> / <code>has</code> / <code>remove</code> are O(1) on average and duplicates are ignored. Create one with <code>Set.new</code>, then <code>add</code> / <code>has</code> / <code>remove</code> / <code>size</code> / <code>clear</code> / <code>members</code>. Arguments are positional. The runtime is spliced in only when a program mentions <code>Set.*</code> (or <code>Dict.*</code>).

docs/language/set/set-add.md

@@ -0,0 +1,22 @@
+---
+id: set-add
+name: Set.add
+category: set
+kind: namespace-method
+tokens: Set.add
+sig: Set.add(s, key)
+tip: Add a member (duplicates ignored).
+order: 1
+ns: Set
+member: add
+---
+
+Adds <code>key</code> to the set. Adding a member that is already present is a harmless no-op.
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    Set.add(tags, "poison")
+  }
+}
+```

docs/language/set/set-clear.md

@@ -0,0 +1,22 @@
+---
+id: set-clear
+name: Set.clear
+category: set
+kind: namespace-method
+tokens: Set.clear
+sig: Set.clear(s)
+tip: Remove every member.
+order: 5
+ns: Set
+member: clear
+---
+
+Empties the set, removing every member while keeping its allocated capacity.
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    Set.clear(tags)
+  }
+}
+```

docs/language/set/set-has.md

@@ -0,0 +1,22 @@
+---
+id: set-has
+name: Set.has
+category: set
+kind: namespace-method
+tokens: Set.has
+sig: Set.has(s, key) -> bool
+tip: Is a member present?
+order: 2
+ns: Set
+member: has
+---
+
+Returns true when <code>key</code> is a member of the set.
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    if Set.has(tags, "poison") { tick() }
+  }
+}
+```

docs/language/set/set-members.md

@@ -0,0 +1,22 @@
+---
+id: set-members
+name: Set.members
+category: set
+kind: namespace-method
+tokens: Set.members
+sig: Set.members(s) -> []pointer
+tip: Every member, as a slice of strings.
+order: 6
+ns: Set
+member: members
+---
+
+Returns every member as a slice of strings, in unspecified order — iterate it with <code>len</code> and indexing.
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    let all = Set.members(tags)
+  }
+}
+```

docs/language/set/set-new.md

@@ -0,0 +1,22 @@
+---
+id: set-new
+name: Set.new
+category: set
+kind: namespace-method
+tokens: Set.new
+sig: Set.new() -> Set
+tip: Create an empty string set.
+order: 0
+ns: Set
+member: new
+---
+
+Creates an empty <code>Set</code> of string members. Add to it with <code>Set.add</code> and test membership with <code>Set.has</code>.
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    let tags = Set.new()
+  }
+}
+```

docs/language/set/set-remove.md

@@ -0,0 +1,22 @@
+---
+id: set-remove
+name: Set.remove
+category: set
+kind: namespace-method
+tokens: Set.remove
+sig: Set.remove(s, key)
+tip: Remove a member.
+order: 3
+ns: Set
+member: remove
+---
+
+Removes <code>key</code> from the set (a no-op if it is not a member).
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    Set.remove(tags, "fire")
+  }
+}
+```

docs/language/set/set-size.md

@@ -0,0 +1,22 @@
+---
+id: set-size
+name: Set.size
+category: set
+kind: namespace-method
+tokens: Set.size
+sig: Set.size(s) -> int
+tip: How many members.
+order: 4
+ns: Set
+member: size
+---
+
+Returns the number of members in the set.
+
+```ludic
+program Demo {
+  handler Step phase Update {
+    let n = Set.size(tags)
+  }
+}
+```