add .mandatory, update learn.sh and sync-skills.sh to use it

learn.sh

@@ -9,24 +9,41 @@ fi
 SKILL_LIST="${AGENT_WORKSPACE}/.skill-list"
 TARGET_DIR="${AGENT_WORKSPACE}/skills"
 CLAW_DIR="$(cd "$(dirname "$0")" && pwd)"
+MANDATORY_FILE="${CLAW_DIR}/.mandatory"
 
-if [[ ! -f "$SKILL_LIST" ]]; then
+mkdir -p "$TARGET_DIR"
+
+# First: install mandatory skills from .mandatory (one per line)
+if [[ -f "$MANDATORY_FILE" ]]; then
+  while IFS= read -r skill_name || [[ -n "$skill_name" ]]; do
+    [[ -z "$skill_name" || "$skill_name" == \#* ]] && continue
+
+    skill_dir="${CLAW_DIR}/${skill_name}"
+    if [[ -d "$skill_dir" ]]; then
+      echo "Installing (mandatory): $skill_name"
+      cp -r "$skill_dir" "${TARGET_DIR}/"
+    else
+      echo "Skipping (not found): $skill_name"
+    fi
+  done < "$MANDATORY_FILE"
+fi
+
+# Then: install skills from .skill-list
+if [[ -f "$SKILL_LIST" ]]; then
+  while IFS= read -r skill_name || [[ -n "$skill_name" ]]; do
+    [[ -z "$skill_name" || "$skill_name" == \#* ]] && continue
+
+    skill_dir="${CLAW_DIR}/${skill_name}"
+    if [[ -d "$skill_dir" ]]; then
+      echo "Installing: $skill_name"
+      cp -r "$skill_dir" "${TARGET_DIR}/"
+    else
+      echo "Skipping (not found): $skill_name"
+    fi
+  done < "$SKILL_LIST"
+else
   echo "Error: .skill-list not found at $SKILL_LIST"
   exit 1
 fi
 
-mkdir -p "$TARGET_DIR"
-
-while IFS= read -r skill_name || [[ -n "$skill_name" ]]; do
-  [[ -z "$skill_name" || "$skill_name" == \#* ]] && continue
-
-  skill_dir="${CLAW_DIR}/${skill_name}"
-  if [[ -d "$skill_dir" ]]; then
-    echo "Installing: $skill_name"
-    cp -r "$skill_dir" "${TARGET_DIR}/"
-  else
-    echo "Skipping (not found): $skill_name"
-  fi
-done < "$SKILL_LIST"
-
-echo "Done."
+echo "Done."