feat(skills): add mt:add-tags skill for Hugo post tag generation

Adds a new skill that analyzes post content and generates 6-7 relevant
tags, checks existing tags, and asks for user confirmation before writing.
Also triggers proactively when committing posts with minimal tags.

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

@@ -0,0 +1,93 @@
+---
+name: mt:add-tags
+description: "Add or update tags in Hugo blog post frontmatter by analyzing post content. Use this skill when the user calls mt:add-tags, wants to add tags to a post, asks about tagging a post, or is about to commit — proactively check if the current post has only generic/minimal tags (e.g., only ['AI-Assisted'] or empty) and offer to generate proper tags. Generate a concise list of 6-7 relevant tags that reflect the actual content. Always ask user to confirm before writing."
+---
+
+## Overview
+
+This skill analyzes Hugo blog post content and generates a short, relevant list of 6-7 tags, then writes them to the post's frontmatter.
+
+**Project context:**
+- Blog: Vietnamese tech content at `content/post/YYYY/MM/DD/index.md`
+- Tags: Mix of English (tech terms, tools, concepts) and Vietnamese where natural
+- Target: 6-7 tags — enough to be discoverable, short enough to stay meaningful
+
+## Workflow
+
+### 1. Find the target post
+
+If the user specifies a post (date, path, or title), use that. Otherwise, use today's post:
+```
+content/post/YYYY/MM/DD/index.md  (today's date in Asia/Ho_Chi_Minh UTC+7)
+```
+
+If no post exists for the target date, tell the user and stop.
+
+### 2. Read and assess existing tags
+
+Read the frontmatter. Check the `tags` field:
+
+- **Missing or empty** → generate fresh tags
+- **Only generic tags** like `["AI-Assisted"]` or `["Newsletter"]` alone → these are placeholders; offer to generate richer tags
+- **Already has 5+ meaningful tags** → show them and ask: *"Post đã có [N] tags: [...]. Bạn có muốn cập nhật không?"* Default: **yes**
+
+### 3. Analyze post content
+
+Read the full post body. Identify:
+- Main topics and technologies discussed
+- Programming languages, frameworks, tools, platforms named
+- Core concepts (e.g., caching, system design, CI/CD)
+- Content type (tutorial, newsletter, opinion piece, deep-dive)
+
+### 4. Generate tags
+
+Produce exactly **6-7 tags**. Follow these guidelines:
+
+**Good tags are:**
+- Specific to what the post actually covers
+- Short and scannable (1-3 words each)
+- Useful for readers finding related content
+
+**Tag categories to draw from (pick what fits):**
+- Technology/tool names: `GitHub Actions`, `Docker`, `PostgreSQL`, `Rust`, `Go`, `Java`
+- Concepts: `CI/CD`, `Caching`, `System Design`, `Performance`, `Security`
+- Content markers: `AI-Assisted` (if AI helped write it), `Newsletter` (if it's a newsletter post), `Tutorial`, `Deep Dive`
+- Domain areas: `DevOps`, `Backend`, `Database`, `Infrastructure`, `Algorithms`
+- Vietnamese topics when relevant: keep in English if it's a tech term with no clean Vietnamese equivalent
+
+**Avoid:**
+- Overly generic tags like `Technology`, `Software`, `Programming` unless the post is truly broad
+- Tags that don't appear in or relate to the actual content
+- More than 7 tags — trim to the most distinctive ones
+
+**Newsletter posts** (title starts with "Newsletter #"): keep `AI-Assisted` and derive 5-6 tags from the main topics covered in that issue.
+
+### 5. Confirm with user
+
+Present the proposed tags before writing:
+
+```
+Đề xuất tags cho "[post title]":
+["Tag1", "Tag2", "Tag3", "Tag4", "Tag5", "Tag6"]
+
+Bạn có muốn áp dụng không? [Y/n]
+```
+
+Wait for confirmation. If the user says no or wants changes, revise accordingly.
+
+### 6. Write tags to frontmatter
+
+Update the `tags` field in the YAML frontmatter. Use this format:
+```yaml
+tags: ["Tag1", "Tag2", "Tag3", "Tag4", "Tag5", "Tag6"]
+```
+
+Replace the entire existing `tags:` line. Preserve all other frontmatter fields exactly.
+
+## Proactive behavior (before commit)
+
+When the user is about to commit (`/commit`, `mt:commit-push-pr`, or similar), check the most recently modified post file. If its tags look minimal (only 1-2 tags, or only `AI-Assisted`/`Newsletter`), say:
+
+> "Post `content/post/.../index.md` chỉ có tags: [...]. Bạn có muốn thêm tags trước khi commit không? [Y/n]"
+
+Default is **yes** — proceed to generate and confirm tags unless the user declines.

.gitignore

@@ -1,5 +1,6 @@
 .idea/
 .hugo_build.lock
+settings.local.json