feat: 80/80 unit tests, real-world examples (FizzBuzz, WordFreq)

- Emitter: def registry (definedGlobals) for symbol emit distinction
- Emitter: cond emits return statements
- Emitter: reduce wraps named functions in closure adapter
- Emitter: clojure.string/* function mappings (split, lower-case, etc.)
- Emitter: statement detection for echo cljRepr wrapping
- Runtime: cljGet supports default value (3 args)
- Runtime: cljStrSplit supports regex patterns via re module
- Examples: fizzbuzz.clj and wordfreq.clj both compile and run correctly
- Tests: emit symbol / emit mangled symbol now pass (80/80)
- Compliance: 233/233 (100%) maintained

lib/cljnim_runtime.nim

@@ -1,6 +1,6 @@
 import cljnim_pvec
 import cljnim_pmap
-import strutils, sequtils, hashes, algorithm, os, osproc, locks, math, random
+import strutils, sequtils, hashes, algorithm, os, osproc, locks, math, random, re
 
 type
   CljKind* = enum
@@ -1338,10 +1338,6 @@ proc cljGet*(m: CljVal, key: CljVal): CljVal =
     else: cljNil()
   else: cljNil()
 
-proc cljGet*(args: seq[CljVal]): CljVal =
-  if args.len < 2: return cljNil()
-  cljGet(args[0], args[1])
-
 proc cljGetDefault*(m: CljVal, key: CljVal, default: CljVal): CljVal =
   if m.isNil: return default
   case m.kind
@@ -1351,6 +1347,13 @@ proc cljGetDefault*(m: CljVal, key: CljVal, default: CljVal): CljVal =
     else: default
   else: default
 
+proc cljGet*(args: seq[CljVal]): CljVal =
+  if args.len < 2: return cljNil()
+  if args.len >= 3:
+    cljGetDefault(args[0], args[1], args[2])
+  else:
+    cljGet(args[0], args[1])
+
 proc cljExInfo*(msg: CljVal, data: CljVal): CljVal =
   var ex = newException(ExInfo, cljStr(msg))
   ex.exData = data
@@ -1663,10 +1666,22 @@ proc cljStrJoin*(args: seq[CljVal]): CljVal =
 
 proc cljStrSplit*(s: CljVal, sep: CljVal): CljVal =
   if s.kind != ckString: raise newException(CatchableError, "split requires a string")
-  let parts = s.strVal.split(cljStr(sep))
+  let sepStr = cljStr(sep)
+  var parts: seq[string]
+  # Check if pattern looks like regex (contains special chars)
+  if sepStr.contains(re"[\\^$.*+?{}()\[\]|]"):
+    try:
+      let regex = re(sepStr)
+      parts = s.strVal.split(regex)
+    except CatchableError:
+      # Fallback to string split if regex is invalid
+      parts = s.strVal.split(sepStr)
+  else:
+    parts = s.strVal.split(sepStr)
   var items: seq[CljVal] = @[]
   for p in parts:
-    items.add(cljString(p))
+    if p.len > 0:  # Skip empty strings from split
+      items.add(cljString(p))
   cljList(items)
 
 proc cljStrReplace*(s: CljVal, match: CljVal, replacement: CljVal): CljVal =