refactor(skills): convert shell scripts to Node.js

Replace bash scripts with cross-platform Node.js equivalents for
mt-add-post and mt-add-tags skills. Update SKILL.md references.

.claude/skills/mt-add-post/SKILL.md

@@ -30,7 +30,7 @@ This skill manages the complete workflow for adding newsletter posts to a Hugo b
 
 For each URL, run the bundled script:
 ```bash
-.claude/skills/mt-add-post/scripts/prepare_url.sh "<url>"
+node .claude/skills/mt-add-post/scripts/prepare-url.js "<url>"
 ```
 
 The script handles:
@@ -53,7 +53,7 @@ Check if `content/post/YYYY/MM/DD/index.md` exists:
 
 Run the bundled script:
 ```bash
-.claude/skills/mt-add-post/scripts/find_newsletter_number.sh
+node .claude/skills/mt-add-post/scripts/find-newsletter-number.js
 ```
 
 This searches backwards from current date to find the most recent newsletter and returns the next number.

.claude/skills/mt-add-post/scripts/find-newsletter-number.js

@@ -0,0 +1,91 @@
+#!/usr/bin/env node
+// Find the most recent newsletter number and return the next one
+// Usage: node find-newsletter-number.js
+// Outputs: The next newsletter number
+
+const fs = require("fs");
+const path = require("path");
+
+const PROJECT_ROOT = path.resolve(__dirname, "../../../..");
+const CONTENT_DIR = path.join(PROJECT_ROOT, "content", "post");
+
+// Extract newsletter number from file content
+function extractNewsletterNumber(filePath) {
+  try {
+    const content = fs.readFileSync(filePath, "utf-8");
+    const match = content.match(/Newsletter\s*#(\d+)/);
+    return match ? parseInt(match[1], 10) : 0;
+  } catch {
+    return 0;
+  }
+}
+
+// Get current date in Asia/Ho_Chi_Minh timezone
+function getCurrentDate() {
+  const now = new Date();
+  const formatter = new Intl.DateTimeFormat("en-CA", {
+    timeZone: "Asia/Ho_Chi_Minh",
+    year: "numeric",
+    month: "2-digit",
+    day: "2-digit",
+  });
+  const parts = formatter.formatToParts(now);
+  return {
+    year: parts.find((p) => p.type === "year").value,
+    month: parts.find((p) => p.type === "month").value,
+    day: parts.find((p) => p.type === "day").value,
+  };
+}
+
+// Scan all year/month/day directories for newsletter posts
+function findMostRecentNewsletter() {
+  let maxNumber = 0;
+
+  // List year directories, sorted descending
+  let years;
+  try {
+    years = fs.readdirSync(CONTENT_DIR)
+      .filter((d) => /^\d{4}$/.test(d))
+      .sort((a, b) => b.localeCompare(a));
+  } catch {
+    return 0;
+  }
+
+  for (const year of years) {
+    const yearDir = path.join(CONTENT_DIR, year);
+    let months;
+    try {
+      months = fs.readdirSync(yearDir)
+        .filter((d) => /^\d{2}$/.test(d))
+        .sort((a, b) => b.localeCompare(a));
+    } catch {
+      continue;
+    }
+
+    for (const month of months) {
+      const monthDir = path.join(yearDir, month);
+      let days;
+      try {
+        days = fs.readdirSync(monthDir)
+          .filter((d) => /^\d{2}$/.test(d))
+          .sort((a, b) => b.localeCompare(a));
+      } catch {
+        continue;
+      }
+
+      for (const day of days) {
+        const filePath = path.join(monthDir, day, "index.md");
+        const num = extractNewsletterNumber(filePath);
+        if (num > maxNumber) maxNumber = num;
+      }
+    }
+
+    // Early exit: if we found a newsletter in this year, no need to go further back
+    if (maxNumber > 0) break;
+  }
+
+  return maxNumber;
+}
+
+const mostRecent = findMostRecentNewsletter();
+console.log(mostRecent + 1);

.claude/skills/mt-add-post/scripts/find_newsletter_number.sh

@@ -1,82 +0,0 @@
-#!/bin/bash
-# Find the most recent newsletter number and return the next one
-# Usage: find_newsletter_number.sh
-# Outputs: The next newsletter number
-
-set -euo pipefail
-
-# Get project root
-PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../../.." && pwd)"
-CONTENT_DIR="$PROJECT_ROOT/content/post"
-
-# Get current date in YYYY/MM/DD format
-CURRENT_YEAR=$(TZ='Asia/Ho_Chi_Minh' date +%Y)
-CURRENT_MONTH=$(TZ='Asia/Ho_Chi_Minh' date +%m)
-CURRENT_DAY=$(TZ='Asia/Ho_Chi_Minh' date +%d)
-
-# Function to find newsletter number in a file
-extract_newsletter_number() {
-    local file="$1"
-    # Look for "Newsletter #N" in front matter title or content
-    grep -oP 'Newsletter\s*#\K\d+' "$file" 2>/dev/null | head -1 || echo "0"
-}
-
-# Function to search for newsletters in date order
-find_most_recent_newsletter() {
-    local max_number=0
-
-    # Current month, going backwards by day
-    for day in {31..1}; do
-        local day_dir=$(printf "%02d" "$day")
-        local check_path="$CONTENT_DIR/$CURRENT_YEAR/$CURRENT_MONTH/$day_dir/index.md"
-        if [[ -f "$check_path" ]]; then
-            local num=$(extract_newsletter_number "$check_path")
-            if ((num > max_number)); then
-                max_number=$num
-            fi
-        fi
-    done
-
-    # Previous months in current year
-    for month in {12..1}; do
-        if [[ $month -ge $CURRENT_MONTH ]]; then
-            continue
-        fi
-        local month_dir=$(printf "%02d" "$month")
-        for day in {31..1}; do
-            local day_dir=$(printf "%02d" "$day")
-            local check_path="$CONTENT_DIR/$CURRENT_YEAR/$month_dir/$day_dir/index.md"
-            if [[ -f "$check_path" ]]; then
-                local num=$(extract_newsletter_number "$check_path")
-                if ((num > max_number)); then
-                    max_number=$num
-                fi
-            fi
-        done
-    done
-
-    # Previous years (check last 5 years)
-    for year in $(seq $((CURRENT_YEAR - 1)) -1 $((CURRENT_YEAR - 5))); do
-        for month in {12..1}; do
-            local month_dir=$(printf "%02d" "$month")
-            for day in {31..1}; do
-                local day_dir=$(printf "%02d" "$day")
-                local check_path="$CONTENT_DIR/$year/$month_dir/$day_dir/index.md"
-                if [[ -f "$check_path" ]]; then
-                    local num=$(extract_newsletter_number "$check_path")
-                    if ((num > max_number)); then
-                        max_number=$num
-                    fi
-                fi
-            done
-        done
-    done
-
-    echo $max_number
-}
-
-# Find most recent and increment
-MOST_RECENT=$(find_most_recent_newsletter)
-NEXT_NUMBER=$((MOST_RECENT + 1))
-
-echo "$NEXT_NUMBER"

.claude/skills/mt-add-post/scripts/prepare-url.js

@@ -0,0 +1,89 @@
+#!/usr/bin/env node
+// URL preparation script for mt-add-post skill
+// Usage: node prepare-url.js "<url>"
+// Outputs: JSON with status, clean_url, type, accessible, duplicate
+
+const { execSync } = require("child_process");
+const path = require("path");
+
+const url = process.argv[2];
+if (!url) {
+  console.error("Usage: node prepare-url.js <url>");
+  process.exit(1);
+}
+
+const PROJECT_ROOT = path.resolve(__dirname, "../../../..");
+
+// Remove common tracking parameters
+function cleanUrl(rawUrl) {
+  try {
+    const parsed = new URL(rawUrl);
+    const trackingParams = [
+      "utm_source", "utm_medium", "utm_campaign", "utm_term", "utm_content",
+      "fbclid", "gclid", "msclkid", "mc_eid",
+    ];
+    trackingParams.forEach((p) => parsed.searchParams.delete(p));
+    return parsed.toString();
+  } catch {
+    // If URL parsing fails, do basic string cleanup
+    return rawUrl.replace(/[?&](utm_[^&]*|fbclid|gclid|msclkid|mc_eid)[^&]*/g, "")
+      .replace(/[?&]$/, "");
+  }
+}
+
+// Check if URL is accessible (returns HTTP status code)
+async function checkAccessibility(targetUrl) {
+  try {
+    const controller = new AbortController();
+    const timeout = setTimeout(() => controller.abort(), 10000);
+    const res = await fetch(targetUrl, {
+      method: "HEAD",
+      redirect: "follow",
+      signal: controller.signal,
+    });
+    clearTimeout(timeout);
+    return res.status.toString();
+  } catch {
+    return "000";
+  }
+}
+
+// Check if URL already exists in project content
+function checkDuplicate(targetUrl) {
+  try {
+    const contentDir = path.join(PROJECT_ROOT, "content");
+    execSync(`grep -rF "${targetUrl}" "${contentDir}"`, { stdio: "pipe" });
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+// Classify URL type by extension
+function classifyUrl(targetUrl) {
+  const lower = targetUrl.toLowerCase();
+  if (/\.(png|jpg|jpeg|gif|webp|svg)(\?.*)?$/.test(lower)) return "image";
+  if (/\.(mp4|webm|mov|avi)(\?.*)?$/.test(lower)) return "video";
+  if (/\.(pdf|doc|docx|xls|xlsx)(\?.*)?$/.test(lower)) return "document";
+  return "article";
+}
+
+// Main
+async function main() {
+  const cleanedUrl = cleanUrl(url);
+  const httpStatus = await checkAccessibility(cleanedUrl);
+  const accessible = httpStatus === "200";
+  const duplicate = checkDuplicate(cleanedUrl);
+  const type = classifyUrl(cleanedUrl);
+
+  console.log(JSON.stringify({
+    original_url: url,
+    clean_url: cleanedUrl,
+    http_status: httpStatus,
+    accessible,
+    duplicate,
+    type,
+  }, null, 2));
+}
+
+main();

.claude/skills/mt-add-post/scripts/prepare_url.sh

@@ -1,78 +0,0 @@
-#!/bin/bash
-# URL preparation script for miti-add-post skill
-# Usage: prepare_url.sh "<url>"
-# Outputs: JSON with status, clean_url, type, accessible, duplicate
-
-set -euo pipefail
-
-URL="$1"
-
-# Remove tracking parameters
-clean_url() {
-    local url="$1"
-    # Remove common tracking parameters
-    url=$(echo "$url" | sed -E 's/[?&](utm_[^&]*|fbclid|gclid|msclkid|mc_eid)[^&]*//g')
-    # Clean up trailing ? or &
-    url=$(echo "$url" | sed -E 's/[?&]$//')
-    echo "$url"
-}
-
-# Check if URL is accessible (returns HTTP status code)
-check_accessibility() {
-    local url="$1"
-    # Use curl to get HTTP status only
-    curl -s -o /dev/null -w "%{http_code}" -L --max-time 10 "$url" 2>/dev/null || echo "000"
-}
-
-# Check if URL is duplicate in project
-check_duplicate() {
-    local url="$1"
-    local project_root="$2"
-    if grep -rF "$url" "$project_root/content" 2>/dev/null; then
-        echo "true"
-    else
-        echo "false"
-    fi
-}
-
-# Classify URL type
-classify_url() {
-    local url="$1"
-    local lower_url=$(echo "$url" | tr '[:upper:]' '[:lower:]')
-
-    # Check for direct assets
-    if echo "$lower_url" | grep -qE '\.(png|jpg|jpeg|gif|webp|svg)(\?.*)?$'; then
-        echo "image"
-    elif echo "$lower_url" | grep -qE '\.(mp4|webm|mov|avi)(\?.*)?$'; then
-        echo "video"
-    elif echo "$lower_url" | grep -qE '\.(pdf|doc|docx|xls|xlsx)(\?.*)?$'; then
-        echo "document"
-    else
-        echo "article"
-    fi
-}
-
-# Main execution
-CLEAN_URL=$(clean_url "$URL")
-HTTP_STATUS=$(check_accessibility "$CLEAN_URL")
-IS_ACCESSIBLE="false"
-if [ "$HTTP_STATUS" = "200" ]; then
-    IS_ACCESSIBLE="true"
-fi
-
-# Get project root (assumes we're in .claude/skills/miti-add-post/scripts)
-PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../../.." && pwd)"
-IS_DUPLICATE=$(check_duplicate "$CLEAN_URL" "$PROJECT_ROOT")
-URL_TYPE=$(classify_url "$CLEAN_URL")
-
-# Output JSON
-cat <<EOF
-{
-  "original_url": "$URL",
-  "clean_url": "$CLEAN_URL",
-  "http_status": "$HTTP_STATUS",
-  "accessible": $IS_ACCESSIBLE,
-  "duplicate": $IS_DUPLICATE,
-  "type": "$URL_TYPE"
-}
-EOF

.claude/skills/mt-add-tags/SKILL.md

@@ -49,7 +49,7 @@ Read the full post body. Identify:
 
 Before generating, run:
 ```bash
-grep -rh "^tags:" content/post/ | tr ',' '\n' | grep -oP '(?<=")[^"]+(?=")' | sort | uniq -c | sort -rn | head -40
+node .claude/skills/mt-add-tags/scripts/list-existing-tags.js
 ```
 When a proposed tag matches an existing one case-insensitively, use the existing casing.
 -->

.claude/skills/mt-add-tags/scripts/list-existing-tags.js

@@ -0,0 +1,65 @@
+#!/usr/bin/env node
+// List existing tags in the repo ranked by frequency
+// Usage: node list-existing-tags.js
+// Outputs: tag count and name, sorted most-used first (top 40)
+//
+// NOTE: This script is NOT currently used by the mt-add-tags skill.
+// Tag normalization is disabled until existing posts have standardized tags.
+// To enable, uncomment step 4a in SKILL.md.
+
+const fs = require("fs");
+const path = require("path");
+
+const PROJECT_ROOT = path.resolve(__dirname, "../../../..");
+const CONTENT_DIR = path.join(PROJECT_ROOT, "content", "post");
+
+// Recursively find all index.md files
+function findIndexFiles(dir) {
+  const results = [];
+  try {
+    const entries = fs.readdirSync(dir, { withFileTypes: true });
+    for (const entry of entries) {
+      const fullPath = path.join(dir, entry.name);
+      if (entry.isDirectory()) {
+        results.push(...findIndexFiles(fullPath));
+      } else if (entry.name === "index.md") {
+        results.push(fullPath);
+      }
+    }
+  } catch {
+    // skip unreadable directories
+  }
+  return results;
+}
+
+// Extract tags from frontmatter
+function extractTags(filePath) {
+  try {
+    const content = fs.readFileSync(filePath, "utf-8");
+    const match = content.match(/^tags:\s*\[([^\]]*)\]/m);
+    if (!match) return [];
+    // Extract quoted strings from the tags array
+    return [...match[1].matchAll(/"([^"]+)"/g)].map((m) => m[1]);
+  } catch {
+    return [];
+  }
+}
+
+// Count tag frequency
+const tagCounts = new Map();
+const files = findIndexFiles(CONTENT_DIR);
+
+for (const file of files) {
+  for (const tag of extractTags(file)) {
+    tagCounts.set(tag, (tagCounts.get(tag) || 0) + 1);
+  }
+}
+
+// Sort by frequency descending, take top 40
+const sorted = [...tagCounts.entries()]
+  .sort((a, b) => b[1] - a[1])
+  .slice(0, 40);
+
+for (const [tag, count] of sorted) {
+  console.log(`${String(count).padStart(6)} ${tag}`);
+}

.claude/skills/mt-add-tags/scripts/list_existing_tags.sh

@@ -1,21 +0,0 @@
-#!/bin/bash
-# List existing tags in the repo ranked by frequency.
-# Usage: list_existing_tags.sh
-# Outputs: tag count and name, sorted most-used first (top 40)
-#
-# NOTE: This script is NOT currently used by the mt-add-tags skill.
-# Tag normalization is disabled until existing posts have standardized tags.
-# To enable, uncomment step 4a in SKILL.md.
-
-set -euo pipefail
-
-PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../../.." && pwd)"
-CONTENT_DIR="$PROJECT_ROOT/content/post"
-
-grep -rh "^tags:" "$CONTENT_DIR" \
-  | tr ',' '\n' \
-  | grep -oP '(?<=")[^"]+(?=")' \
-  | sort \
-  | uniq -c \
-  | sort -rn \
-  | head -40