fix(skills): prefer newsletter terminology

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

@@ -42,7 +42,7 @@ node scripts/newsletter/find-substack-post.js --uuid <uuid>
 - `found: false` after `--deep` → no source post; go to step 3 (ask) and/or step 4 (add publication).
 
 **When `found: true` — pick the label (confirm-from-candidates):**
-ByteByteGo doesn't attach captions to images (verified: empty `alt`, no `<figcaption>`), and image order can't be mapped to titles automatically because sponsor/video items interleave. So the script returns `candidates` — the issue's topic titles from the post's TOC. Pick the label this way:
+ByteByteGo doesn't attach captions to images (verified: empty `alt`, no `<figcaption>`), and image order can't be mapped to titles automatically because sponsor/video items interleave. So the script returns `candidates` — the newsletter post's topic titles from the post's TOC. Pick the label this way:
 1. If `caption` is non-empty (some publications do caption images) → propose it as the default.
 2. Otherwise present `candidates` to the user via `AskUserQuestion` (the correct title is in this list):
    - "Image is from **[postTitle]** (`postUrl`). Which title matches it?"

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

@@ -73,7 +73,7 @@ Produce **2-3 tags** for regular posts, **6-7 tags** for newsletter posts (title
 - 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, totalling 6-7 tags.
+**Newsletter posts** (title starts with "Newsletter #"): keep `AI-Assisted` and derive 5-6 tags from the main topics covered in that newsletter, totalling 6-7 tags.
 
 ### 5. Confirm with user
 

.claude/skills/mt-add-url/references/newsletter-post-mechanics.md

@@ -22,6 +22,10 @@ node scripts/newsletter/find-newsletter-number.js
 ```
 Searches backwards from today for the most recent newsletter and returns the next number. Only needed when **creating** a new post.
 
+## 2a. Terminology
+
+Refer to each numbered publication as a **newsletter**, not an issue. Use wording like `Newsletter #120`, `add newsletter 120`, or `add Newsletter #120` in reports and commit messages.
+
 ## 3. New post template
 
 ```markdown
@@ -90,7 +94,7 @@ When a subsection (e.g. `**Videos:**`) already exists, append under it; otherwis
 
 ## 6. Error handling
 
-| Issue | Action |
+| Problem | Action |
 |-------|--------|
 | URL inaccessible | Skip, note in report |
 | Duplicate URL | Skip, note in report |