Add LinkedIn Post Formatter skill and LinkedIn Post Writer agent 🤖🤖🤖 (#1392)

* feat(skills,agents): add LinkedIn post formatter skill and writer agent

Add self-contained LinkedIn post formatting skill with Unicode bold/italic
character mapping and engagement-optimized post structure patterns.
Add LinkedIn Post Writer agent for transforming raw content into
copy-paste-ready LinkedIn posts. No external service dependencies.

* fix: address Copilot review comments on PR #1392

- Correct Unicode range header to include digit range (U+1D7EC–U+1D7F5)
- Add explicit instruction to load references/unicode-charmap.md
- Fix LinkedIn casing in README.agents.md (Linkedin → LinkedIn)

* fix: use display name for LinkedIn agent to preserve brand casing

The name field now uses 'LinkedIn Post Writer' instead of the slug
format, ensuring the auto-generated README table shows correct casing.

---------

Co-authored-by: Shailesh Mishra <shaileshmishra@example.com>

skills/linkedin-post-formatter/SKILL.md

@@ -0,0 +1,171 @@
+---
+name: linkedin-post-formatter
+description: 'Format and draft compelling LinkedIn posts using Unicode bold/italic styling, visual separators, structured sections, and engagement-optimized patterns. USE FOR: draft LinkedIn post, format text for LinkedIn, create social media post, write thought leadership post, convert content to LinkedIn format, LinkedIn carousel text, Unicode bold italic formatting.'
+---
+
+# LinkedIn Post Formatter
+
+Transform raw content, ideas, or technical material into polished, engagement-optimized LinkedIn posts using Unicode typography and proven structural patterns.
+
+## Overview
+
+LinkedIn only supports plain text — no Markdown rendering, no rich formatting. This skill uses Unicode Mathematical Alphanumeric Symbols to simulate bold, italic, and bold-italic text that renders natively in the LinkedIn editor without any external tools.
+
+## Unicode Typography Reference
+
+When converting plain text into Unicode-styled LinkedIn text, first load and use `references/unicode-charmap.md` as the authoritative character mapping reference.
+
+Apply these character mappings to create visual emphasis in plain text:
+
+### Bold (Mathematical Sans-Serif Bold)
+
+Use bold for key phrases, section headers, and emphasis words.
+
+| Plain | Unicode Bold |
+|-------|-------------|
+| A-Z   | 𝗔-𝗭         |
+| a-z   | 𝗮-𝘇         |
+| 0-9   | 𝟬-𝟵         |
+
+### Italic (Mathematical Sans-Serif Italic)
+
+Use italic for subtle emphasis, technical terms, or quotes.
+
+| Plain | Unicode Italic |
+|-------|---------------|
+| A-Z   | 𝘈-𝘡           |
+| a-z   | 𝘢-𝘻           |
+
+### Bold-Italic (Mathematical Sans-Serif Bold Italic)
+
+Use sparingly for maximum emphasis.
+
+| Plain | Unicode Bold-Italic |
+|-------|-------------------|
+| A-Z   | 𝘼-𝙕               |
+| a-z   | 𝙖-𝙯               |
+
+## Visual Separators
+
+Use these characters to create visual structure:
+
+- **Section divider**: `━━━━━━━━━━━━━━━━━━━━━━` (box-drawing heavy horizontal)
+- **Bullet points**: `◈` (diamond with dot) or `◎` (bullseye)
+- **Arrow flow**: `↓` for vertical flow, `→` for horizontal continuation
+- **Sub-points**: `↳` for indented sub-items
+- **Numbered items**: Use bold Unicode digits `𝟭. 𝟮. 𝟯.` etc.
+
+## Post Structure Patterns
+
+### Pattern 1: Hook → Content → CTA (General Purpose)
+
+```
+[Bold hook line — provocative statement or question]
+
+[1-2 lines of context setting the stage]
+
+━━━━━━━━━━━━━━━━━━━━━━
+
+[Main content with bold section headers]
+[Bullet points using ◈ or numbered with bold digits]
+
+━━━━━━━━━━━━━━━━━━━━━━
+
+[Bold takeaway or summary]
+
+[Call to action — repost, comment, or grab resource]
+
+#Hashtags
+```
+
+### Pattern 2: Listicle (Numbered Insights)
+
+```
+[Bold opening line with a strong claim]
+
+[Setup line explaining what follows]
+
+𝟭. [Bold item title]
+   [Supporting detail]
+
+𝟮. [Bold item title]
+   [Supporting detail]
+
+...
+
+𝗧𝗵𝗲 𝗸𝗲𝘆 𝘁𝗮𝗸𝗲𝗮𝘄𝗮𝘆: [Summary in italic]
+
+#Hashtags
+```
+
+### Pattern 3: Story → Lesson (Thought Leadership)
+
+```
+[Italic opening with a personal or observed moment]
+
+[2-3 short paragraphs telling the story]
+
+━━━━━━━━━━━━━━━━━━━━━━
+
+𝗧𝗵𝗲 𝗹𝗲𝘀𝘀𝗼𝗻:
+
+[Bold lesson or principle extracted from the story]
+
+[CTA]
+
+#Hashtags
+```
+
+### Pattern 4: Resource Share (Cheatsheet/Guide/Tool)
+
+```
+[Hook: "If you do X, you cannot miss this..."]
+
+[Brief description of what the resource covers]
+
+━━━━━━━━━━━━━━━━━━━━━━
+
+[Bold section count]. [Bold section titles as numbered list]
+
+━━━━━━━━━━━━━━━━━━━━━━
+
+𝗧𝗵𝗲 𝗿𝗲𝗮𝗹 𝘁𝗮𝗸𝗲𝗮𝘄𝗮𝘆:
+
+[Why this resource matters — bold key phrase]
+
+[Grab it / Share it CTA]
+
+♻️ 𝗥𝗲𝗽𝗼𝘀𝘁 if this is useful to your network.
+
+#Hashtags
+```
+
+## Formatting Rules
+
+1. **Line breaks matter**: LinkedIn collapses multiple blank lines. Use single blank lines between paragraphs.
+2. **Hook above the fold**: The first 2-3 lines must compel the reader to click "see more." Front-load value.
+3. **Short paragraphs**: 1-3 sentences max per paragraph. Wall of text kills engagement.
+4. **Bold sparingly**: Bold key phrases and headers, not entire paragraphs.
+5. **Italic for nuance**: Use italic for technical terms, internal thoughts, or subtle emphasis.
+6. **Hashtags at the end**: 5-8 relevant hashtags on the last line. No mid-post hashtags.
+7. **No emojis in body** unless the user explicitly requests them. Exception: one strategic emoji in CTA (♻️ for repost).
+8. **Character limit**: LinkedIn posts can be up to 3000 characters. Aim for 1500-2500 for optimal engagement.
+9. **No URLs in body**: LinkedIn suppresses reach for posts with links. Add links in comments instead. Mention "link in comments" or "grab it below" as CTA.
+
+## Engagement Optimization
+
+- **Opening hooks that work**: Questions, bold claims, "If you do X...", contrarian takes, surprising stats.
+- **Closing CTAs that work**: "♻️ 𝗥𝗲𝗽𝗼𝘀𝘁 if...", "Save this for later", "Tag someone who needs this", "What's your take? 👇"
+- **Whitespace is your friend**: Dense text gets scrolled past. Airy, scannable layout wins.
+- **The "see more" hook**: LinkedIn truncates posts after ~210 characters on desktop. Make sure the first 2 lines create enough curiosity to click.
+
+## Process
+
+1. Analyze the source content (text, HTML, image, or idea).
+2. Identify the best post structure pattern (Hook→Content→CTA, Listicle, Story→Lesson, Resource Share).
+3. Extract the core message and 3-5 key points.
+4. Apply Unicode bold/italic formatting to headers and emphasis words using `references/unicode-charmap.md`.
+5. Add visual separators between sections.
+6. Write a compelling hook for the opening.
+7. Add a CTA and hashtags at the end.
+8. Verify the post is copy-paste ready for LinkedIn.