fix(compiler): translate Map/Set expression patterns to JavaScript (#18)

- x in someSet → someSet.has(x)
- x in someMap.keys → someMap.has(x)
- x notIn someMap.keys → !someMap.has(x)
- m[k] → m.get(k) for Map state variables
- s.size() → s.size (property, not method)
- Track Map-typed state variables via mapVarNames for accurate .get() translation
- Thread mapVarNames through emitAction and rewriteExpr

All 41 tests passing. TigerBeetleLedger now generates correct TypeScript
with .get() for Map access and .has() for Set membership.

Part of M0.1: Fix TS generator bugs (speckl#18)

out/ToggleSwitch.wat

@@ -0,0 +1,71 @@
+;; Auto-generated by speckl-compile from ToggleSwitch
+;; Compile: wat2wasm ToggleSwitch.wat -o ToggleSwitch.wasm
+
+(module
+  ;; Host imports for Map/Set/alloc
+  (import "speckl" "map_create" (func $map_create (result i32)))
+  (import "speckl" "map_set" (func $map_set (param i32 i32 i32)))
+  (import "speckl" "map_get" (func $map_get (param i32 i32) (result i32)))
+  (import "speckl" "map_has" (func $map_has (param i32 i32) (result i32)))
+  (import "speckl" "map_remove" (func $map_remove (param i32 i32)))
+  (import "speckl" "set_create" (func $set_create (result i32)))
+  (import "speckl" "set_add" (func $set_add (param i32 i32)))
+  (import "speckl" "set_has" (func $set_has (param i32 i32) (result i32)))
+  (import "speckl" "set_size" (func $set_size (param i32) (result i32)))
+  (import "speckl" "alloc" (func $alloc (param i32) (result i32)))
+  (import "speckl" "write_i32" (func $write_i32 (param i32 i32)))
+  (import "speckl" "write_f64" (func $write_f64 (param i32 f64)))
+
+  ;; Linear memory (exported so host can read state)
+  (memory (export "memory") 1)
+
+  ;; State globals
+  (global $isOn (mut i32) (i32.const 0))
+
+  ;; ---- init ----
+  (func $init (export "init")
+    (i32.const 0)
+    (global.set $isOn)
+  )
+
+  ;; ---- Actions ----
+    ;; action: TurnOn
+  (func $TurnOn (export "TurnOn")  (result i32)
+    
+    ;; require: not isOn
+    ;; Complex guard not compiled: not isOn
+    ;; isOn := true
+    (i32.const 0) ;; uncompiled expr: true
+    (global.set $isOn)
+    (global.get $isOn)
+    (return)
+  )
+
+  ;; action: TurnOff
+  (func $TurnOff (export "TurnOff")  (result i32)
+    
+    ;; require: isOn
+    ;; Complex guard not compiled: isOn
+    ;; isOn := false
+    (i32.const 0) ;; uncompiled expr: false
+    (global.set $isOn)
+    (global.get $isOn)
+    (return)
+  )
+
+  ;; ---- getState ----
+  (func $getState (export "getState") (result i32 i32)
+    (i32.const 0)
+    (global.get $isOn)
+    (i32.store)
+    (i32.const 0)
+    (i32.const 4)
+  )
+
+  
+  ;; checkConstraints — runtime constraint evaluation stub
+  (func $checkConstraints (export "checkConstraints") (result i32)
+    ;; TODO: evaluate constraint expressions at runtime
+    (i32.const 1)
+  )
+)