fix: auto-migrate customized skills to skills-local/ on sync (#359)

packages/mosaic/framework/tools/_scripts/mosaic-sync-skills

@@ -56,38 +56,66 @@ if [[ $fetch -eq 1 ]]; then
   if [[ -d "$SKILLS_REPO_DIR/.git" ]]; then
     echo "[mosaic-skills] Updating skills source: $SKILLS_REPO_DIR"
 
-    # Detect ANY dirty state: modified, staged, or untracked files.
-    # Use git status --porcelain which catches everything pull --rebase cares about.
+    # ── Detect dirty state ──────────────────────────────────────────────
     dirty=""
     dirty="$(git -C "$SKILLS_REPO_DIR" status --porcelain 2>/dev/null || true)"
 
     if [[ -n "$dirty" ]]; then
-      echo "[mosaic-skills] Stashing local changes (including untracked)..."
-      git -C "$SKILLS_REPO_DIR" stash push -q --include-untracked -m "mosaic-sync-skills auto-stash" 2>/dev/null || {
-        echo "[mosaic-skills] WARN: stash failed — skipping pull, using existing checkout" >&2
-        dirty="skip-pull"
-      }
-    fi
+      # ── Auto-migrate customized skills to skills-local/ ─────────────
+      # Instead of stash/pop (fragile, merge conflicts), we:
+      #   1. Identify which skill dirs contain user edits
+      #   2. Copy those full skill dirs into skills-local/ (preserving edits)
+      #   3. Reset the repo clean so pull always succeeds
+      #   4. skills-local/ takes precedence during linking, so edits win
 
-    if [[ "$dirty" != "skip-pull" ]]; then
-      if ! git -C "$SKILLS_REPO_DIR" pull --rebase 2>/dev/null; then
-        echo "[mosaic-skills] WARN: pull failed — continuing with existing checkout" >&2
-        # Abort any in-progress rebase so the repo isn't left in a broken state
-        git -C "$SKILLS_REPO_DIR" rebase --abort 2>/dev/null || true
+      SOURCE_SKILLS_SUBDIR="$SKILLS_REPO_DIR/skills"
+      migrated=()
+
+      while IFS= read -r line; do
+        # porcelain format: XY <path>  — extract the file path
+        file="${line:3}"
+        # Only migrate files under skills/ subdir in the repo
+        if [[ "$file" == skills/* ]]; then
+          # Extract the skill directory name (first path component after skills/)
+          skill_name="${file#skills/}"
+          skill_name="${skill_name%%/*}"
+
+          # Skip if already migrated this skill in this run
+          local_skill_dir="$MOSAIC_LOCAL_SKILLS_DIR/$skill_name"
+          if [[ -d "$local_skill_dir" ]]; then
+            continue
+          fi
+
+          # Skip if skill_name is empty or hidden
+          if [[ -z "$skill_name" || "$skill_name" == .* ]]; then
+            continue
+          fi
+
+          # Copy the skill (with user's edits) from repo working tree to skills-local/
+          if [[ -d "$SOURCE_SKILLS_SUBDIR/$skill_name" ]]; then
+            cp -R "$SOURCE_SKILLS_SUBDIR/$skill_name" "$local_skill_dir"
+            migrated+=("$skill_name")
+          fi
+        fi
+      done <<< "$dirty"
+
+      if [[ ${#migrated[@]} -gt 0 ]]; then
+        echo "[mosaic-skills] Migrated ${#migrated[@]} customized skill(s) to skills-local/:"
+        for s in "${migrated[@]}"; do
+          echo "  → $MOSAIC_LOCAL_SKILLS_DIR/$s"
+        done
+        echo "[mosaic-skills] Your edits are preserved there and take precedence over canonical."
       fi
+
+      # Reset repo to clean state so pull always works
+      echo "[mosaic-skills] Resetting source repo to clean state..."
+      git -C "$SKILLS_REPO_DIR" checkout . 2>/dev/null || true
+      git -C "$SKILLS_REPO_DIR" clean -fd 2>/dev/null || true
     fi
 
-    # Restore stashed changes if we stashed anything
-    if [[ -n "$dirty" && "$dirty" != "skip-pull" ]]; then
-      echo "[mosaic-skills] Restoring local changes..."
-      git -C "$SKILLS_REPO_DIR" stash pop -q 2>/dev/null || \
-        echo "[mosaic-skills] WARN: stash pop had conflicts — check $SKILLS_REPO_DIR" >&2
-    fi
-
-    # Hint: customized skills belong in skills-local/, not in the canonical repo
-    if [[ -n "$dirty" ]]; then
-      echo "[mosaic-skills] TIP: Put customized skills in $MOSAIC_LOCAL_SKILLS_DIR/ instead"
-      echo "[mosaic-skills]      Files there are never overwritten and take precedence."
+    if ! git -C "$SKILLS_REPO_DIR" pull --rebase 2>/dev/null; then
+      echo "[mosaic-skills] WARN: pull failed — continuing with existing checkout" >&2
+      git -C "$SKILLS_REPO_DIR" rebase --abort 2>/dev/null || true
     fi
   else
     echo "[mosaic-skills] Cloning skills source to: $SKILLS_REPO_DIR"