fix(viz): make local verification portable

Avoid Bash 4-only mapfile in the style compliance test and let the viz parser handle simple frontmatter when PyYAML is absent, so the rebased full suite can run in the local macOS environment.

Author: Horacehxw

tests/test-style-compliance.sh

@@ -41,7 +41,10 @@ _pass() { printf '\033[0;32mPASS\033[0m: %s\n' "$1"; PASS_COUNT=$((PASS_COUNT+1)
 _fail() { printf '\033[0;31mFAIL\033[0m: %s\n' "$1"; FAIL_COUNT=$((FAIL_COUNT+1)); }
 
 # Step 1: every .sh and .py under viz/.
-mapfile -t CORE_FILES < <(
+CORE_FILES=()
+while IFS= read -r f; do
+    CORE_FILES+=("$f")
+done < <(
     find "$PLUGIN_ROOT/viz" \
         -type f \( -name '*.sh' -o -name '*.py' \) \
         -not -path "*/__pycache__/*" \

viz/server/parser.py

@@ -11,14 +11,60 @@
 import os
 import re
 import subprocess
-import yaml
 from datetime import datetime
 
 import rlcr_sources
 
+try:
+    import yaml
+except ModuleNotFoundError:  # pragma: no cover - exercised by shell tests
+    yaml = None
+
 logger = logging.getLogger(__name__)
 
 
+def _coerce_yaml_scalar(value):
+    """Parse the simple scalar values used in Humanize state frontmatter."""
+    value = value.strip()
+    if value == '':
+        return ''
+    if (value.startswith('"') and value.endswith('"')) or (
+        value.startswith("'") and value.endswith("'")
+    ):
+        return value[1:-1]
+    lowered = value.lower()
+    if lowered == 'true':
+        return True
+    if lowered == 'false':
+        return False
+    if lowered in {'null', 'none', '~'}:
+        return None
+    if re.fullmatch(r'-?[0-9]+', value):
+        try:
+            return int(value)
+        except ValueError:
+            return value
+    return value
+
+
+def _safe_load_frontmatter(text):
+    """Load frontmatter, falling back to a small key/value parser without PyYAML."""
+    if yaml is not None:
+        return yaml.safe_load(text) or {}
+
+    meta = {}
+    for raw_line in text.splitlines():
+        line = raw_line.strip()
+        if not line or line.startswith('#') or ':' not in line:
+            continue
+        key, value = line.split(':', 1)
+        key = key.strip()
+        if not re.fullmatch(r'[A-Za-z_][A-Za-z0-9_-]*', key):
+            continue
+        meta[key] = _coerce_yaml_scalar(value)
+    return meta
+
+
 def _derive_project_root(session_dir):
     """Return the project root for a ``.humanize/rlcr/<session>`` path."""
     rlcr_dir = os.path.dirname(session_dir)
@@ -64,8 +110,8 @@ def parse_yaml_frontmatter(filepath):
         return {}, content
 
     try:
-        meta = yaml.safe_load(parts[1]) or {}
-    except yaml.YAMLError:
+        meta = _safe_load_frontmatter(parts[1])
+    except Exception:
         meta = {}
 
     body = parts[2].strip()