fix(skills): use yaml.safe_load for frontmatter parsing to handle multiline descriptions

The hand-rolled line-by-line YAML parser treated each line independently,
so YAML multiline scalars (folded `>` and literal `|`) were captured as
the literal characters ">" or "|" instead of the actual text content.

nanobot/agent/skills.py

@@ -6,6 +6,8 @@ import re
 import shutil
 from pathlib import Path
 
+import yaml
+
 # Default builtin skills directory (relative to this file)
 BUILTIN_SKILLS_DIR = Path(__file__).parent.parent / "skills"
 
@@ -171,11 +173,19 @@ class SkillsLoader:
             return content[match.end():].strip()
         return content
 
-    def _parse_nanobot_metadata(self, raw: str) -> dict:
-        """Parse skill metadata JSON from frontmatter (supports nanobot and openclaw keys)."""
-        try:
-            data = json.loads(raw)
-        except (json.JSONDecodeError, TypeError):
+    def _parse_nanobot_metadata(self, raw: object) -> dict:
+        """Extract nanobot/openclaw metadata from a frontmatter field.
+
+        ``raw`` may be a dict (already parsed by yaml.safe_load) or a JSON str.
+        """
+        if isinstance(raw, dict):
+            data = raw
+        elif isinstance(raw, str):
+            try:
+                data = json.loads(raw)
+            except (json.JSONDecodeError, TypeError):
+                return {}
+        else:
             return {}
         if not isinstance(data, dict):
             return {}
@@ -193,8 +203,8 @@ class SkillsLoader:
 
     def _get_skill_meta(self, name: str) -> dict:
         """Get nanobot metadata for a skill (cached in frontmatter)."""
-        meta = self.get_skill_metadata(name) or {}
-        return self._parse_nanobot_metadata(meta.get("metadata", ""))
+        raw_meta = self.get_skill_metadata(name) or {}
+        return self._parse_nanobot_metadata(raw_meta.get("metadata"))
 
     def get_always_skills(self) -> list[str]:
         """Get skills marked as always=true that meet requirements."""
@@ -203,7 +213,7 @@ class SkillsLoader:
             for entry in self.list_skills(filter_unavailable=True)
             if (meta := self.get_skill_metadata(entry["name"]) or {})
             and (
-                self._parse_nanobot_metadata(meta.get("metadata", "")).get("always")
+                self._parse_nanobot_metadata(meta.get("metadata")).get("always")
                 or meta.get("always")
             )
         ]
@@ -224,10 +234,15 @@ class SkillsLoader:
         match = _STRIP_SKILL_FRONTMATTER.match(content)
         if not match:
             return None
-        metadata: dict[str, str] = {}
-        for line in match.group(1).splitlines():
-            if ":" not in line:
-                continue
-            key, value = line.split(":", 1)
-            metadata[key.strip()] = value.strip().strip('"\'')
+        try:
+            parsed = yaml.safe_load(match.group(1))
+        except yaml.YAMLError:
+            return None
+        if not isinstance(parsed, dict):
+            return None
+        # yaml.safe_load returns native types (int, bool, list, etc.);
+        # keep values as-is so downstream consumers get correct types.
+        metadata: dict[str, object] = {}
+        for key, value in parsed.items():
+            metadata[str(key)] = value
         return metadata