style: enhance Telegram message formatting with visual hierarchy

Improved markdownToHtml converter for richer Telegram messages:
- Heading hierarchy: h1 (🚀+separator), h2 (█), h3 (▸), h4 (●)
- Multi-line blockquote merging
- Indented bullet lists
- Markdown table support (rendered as <pre>)
- Horizontal rule rendering
- Language class on fenced code blocks

Co-Authored-By: zcode <noreply@zcode.dev>

CHANGELOG.md

@@ -55,6 +55,24 @@ recovers cleanly from stale processes, and has zero EADDRINUSE crashes.
 
 ## [2.0.0] - 2026-05-06
 
+### 🎨 Improved
+
+#### Telegram Message Formatting Overhaul
+
+Enhanced the `markdownToHtml` converter in `src/bot/message-sender.js` to produce
+visually rich, well-structured Telegram messages:
+
+- **Heading hierarchy** — h1 gets 🚀 + separator line, h2 gets █ block marker,
+  h3 gets ▸ triangle, h4 gets ● dot — all bold, visually distinct
+- **Multi-line blockquotes** — consecutive `>` lines now merge into a single
+  `<blockquote>` element instead of one per line
+- **Indented bullet lists** — `  • ` with leading spaces for better readability
+- **Table support** — Markdown tables (`| col | col |`) rendered as `<pre>` blocks
+- **Horizontal rules** — `---` and `***` render as ──── separator lines
+- **Code blocks** — fenced code blocks get `<pre><code>` with language class attribute
+- Cleaner vertical spacing (excessive blank lines collapsed)
+
+
 ### 🎉 Major Release - Ruflo Integration Complete
 
 Complete integration of Ruflo's multi-agent orchestration system with comprehensive documentation update.