docs: update project-state, add post-guideline reference

- Refresh project-state.md with all completed work this session
- Add docs/post-guideline.md (title case, locale structure, frontmatter, publish flow)
- Reference it in README + hoelee-blog skill

docs/post-guideline.md

@@ -0,0 +1,95 @@
+# Post-Writing Guideline
+
+A single reference for writing a post on blog.hoelee.com. Read this **before** creating or editing any post. It consolidates the style, locale, and frontmatter rules — the "how to write it correctly the first time" checklist.
+
+> Broader *what-to-write* strategy (categories, post types, cadence, anti-patterns) lives in `content-guide.md`. This file is the *how* — mechanics and style.
+
+---
+
+## 1. File location & language (enforced by code)
+
+| Language | Path | URL |
+|---|---|---|
+| English | `src/content/posts/<slug>.md` | `/posts/<slug>/` |
+| Chinese | `src/content/posts/zh/<slug>.md` | `/posts/zh/<slug>/` |
+
+- **Do NOT set a `lang:` field** in frontmatter — language is derived from the folder.
+- English is primary. Chinese is selective (2–3 flagship case studies). No Malay.
+- To make a Chinese translation of a post, give it the **same filename** in the `zh/` folder — the language switcher auto-links them. If filenames differ, add a `translation: "zh/<other-slug>"` field to link them manually.
+
+---
+
+## 2. Title style — Title Case
+
+All English post titles use **Title Case** (capitalize the first letter of every significant word):
+
+- ✅ `How I Host This Blog: Astro, Gitea Actions, and Self-Hosted CI/CD`
+- ✅ `Hello, World — About This Blog`
+- ❌ `How I host this blog: ...`
+
+Exceptions stay lowercase (articles, prepositions, conjunctions — but our house style capitalizes them after punctuation like `—` or `:` for a clean look): "About", "This", "And", "and" are all acceptable; be **consistent**.
+
+Chinese titles need no capitalization change.
+
+---
+
+## 3. Frontmatter shape
+
+```yaml
+---
+title: "How I Built the DigiKedai Telegram AI Bot"   # Title Case
+description: "A ~155-char meta description with the target keyword."
+pubDate: 2026-09-06
+updatedDate: 2026-09-10                    # optional, when revised
+category: case-studies                      # one of the 7 below
+tags: ["telegram", "n8n", "docker", "cloudflare"]
+translation: "zh/how-i-built-digikedai-bot" # optional, only if slug differs from zh counterpart
+ogImage: "/og/digikedai-bot.png"            # optional, 1200×630 custom image
+draft: false                                 # true = hidden from build
+---
+```
+
+### Categories (the only 7 allowed)
+`engineering` · `devops` · `ai` · `web3` · `tutorials` · `case-studies` · `notes`
+
+---
+
+## 4. The "hard job → post" template
+
+When you finish a difficult piece of work, use this shape — it's simultaneously a tutorial, a case study, and a proof-of-expertise:
+
+```
+① The problem        → phrased as the searchable question a learner would type
+② What I tried & why it failed → the debugging story (no one else can copy this)
+③ The fix            → runnable code/config, explained
+④ What I'd do differently → shows judgment
+⑤ The result         → one quantified outcome
+```
+
+---
+
+## 5. Language & identity rules
+
+- **Business framing:** website design & development is the primary business; email hosting is a **side offering** — never describe it as "an email-hosting business".
+- **Name:** "Lee Teong Hoe" / "Mr Hoelee" — identical across blog, LinkedIn, GitHub, git.hoelee.com.
+- **No overclaiming**, especially Web3 (learning projects, not production DeFi).
+
+---
+
+## 6. Code blocks
+
+- Wrap code in fenced blocks with the language tag (```yaml, ```bash, ```ts).
+- Keep code/commands in their **original language** (don't translate code or commands inside a Chinese post).
+- The copy button is added automatically by the layout — no action needed.
+
+---
+
+## 7. Publish flow
+
+1. Write the `.md` file in the correct folder (see §1).
+2. `npm run build` locally to confirm it compiles (optional but recommended).
+3. Commit + push to both remotes:
+   ```bash
+   git push origin main && git push github main
+   ```
+4. Gitea Actions CI builds and deploys automatically; verify with `curl -I https://blog.hoelee.com/posts/<slug>/` → 200.