fix: Phase 5 — MEDIUM #27,30,31 + LOW #25,41 complete cleanup

Files modified (6):
  compiler/parser/parser.go — #27: Add currentUpper() helper
    Replaces 30 strings.ToUpper(p.current.Literal) calls
  compiler/parser/stmtreg.go — Remove now-unused strings import
  compiler/parser/expr.go — #30: Document comma expr Harbour semantics
  compiler/gengo/gengo.go — #31: Replace 8 TODO comments with WARN
    Macro expr now emits MacroPush() instead of TODO
  compiler/token/token.go — #25: Replace itoa with strconv.Itoa
    #41: Add 50+ missing kindNames entries for complete String()

Issues resolved: #25,27,30,31,41
Total fixed: 39/53

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/.pdca-status.json

@@ -1,6 +1,6 @@
 {
   "version": "2.0",
-  "lastUpdated": "2026-04-01T08:11:30.993Z",
+  "lastUpdated": "2026-04-01T11:59:53.709Z",
   "activeFeatures": [
     "hbrt",
     "hbrtl",
@@ -72,7 +72,7 @@
       "documents": {},
       "timestamps": {
         "started": "2026-03-27T11:22:43.083Z",
-        "lastUpdated": "2026-04-01T02:53:26.889Z"
+        "lastUpdated": "2026-04-01T11:55:48.928Z"
       },
       "lastFile": "/mnt/d/charles/five/compiler/token/token.go"
     },
@@ -111,9 +111,9 @@
       "documents": {},
       "timestamps": {
         "started": "2026-03-27T11:38:35.393Z",
-        "lastUpdated": "2026-04-01T02:57:07.253Z"
+        "lastUpdated": "2026-04-01T11:59:53.709Z"
       },
-      "lastFile": "/mnt/d/charles/five/compiler/parser/stmtreg.go"
+      "lastFile": "/mnt/d/charles/five/compiler/parser/parser.go"
     },
     "gengo": {
       "phase": "do",
@@ -280,7 +280,7 @@
   "session": {
     "startedAt": "2026-03-27T06:06:49.620Z",
     "onboardingCompleted": false,
-    "lastActivity": "2026-04-01T08:11:30.993Z"
+    "lastActivity": "2026-04-01T11:59:53.709Z"
   },
   "history": [
     {
@@ -5790,6 +5790,42 @@
       "feature": "five",
       "phase": "do",
       "action": "updated"
+    },
+    {
+      "timestamp": "2026-04-01T09:06:37.685Z",
+      "feature": "parser",
+      "phase": "do",
+      "action": "updated"
+    },
+    {
+      "timestamp": "2026-04-01T11:55:48.928Z",
+      "feature": "token",
+      "phase": "do",
+      "action": "updated"
+    },
+    {
+      "timestamp": "2026-04-01T11:56:18.336Z",
+      "feature": "parser",
+      "phase": "do",
+      "action": "updated"
+    },
+    {
+      "timestamp": "2026-04-01T11:56:49.851Z",
+      "feature": "parser",
+      "phase": "do",
+      "action": "updated"
+    },
+    {
+      "timestamp": "2026-04-01T11:58:41.033Z",
+      "feature": "parser",
+      "phase": "do",
+      "action": "updated"
+    },
+    {
+      "timestamp": "2026-04-01T11:59:53.709Z",
+      "feature": "parser",
+      "phase": "do",
+      "action": "updated"
     }
   ]
 }