Day 40: Live Markdown Editor & Previewer

[Copilot]

Chimera's daily evolution adding a split-view Markdown editor with live HTML preview as a new dashboard section.

New modules

• src/markdownEditor.ts — Pure rendering engine: headings H1–H6, bold/italic/strikethrough, inline/fenced code with language classes, blockquotes, ordered/unordered lists, tables, links, images, HR. HTML-escapes all code content to prevent XSS. Exports getMarkdownStats and insertSnippet helpers.
• src/markdownEditorUI.ts — Split-pane UI wiring the renderer to a live textarea. Features:
  • 14-button formatting toolbar (wraps selection or inserts placeholder)
  • Ctrl+B / Ctrl+I shortcuts inside the editor; Tab inserts two spaces
  • Three starter templates: README, Blog Post, Meeting Notes
  • Copy-to-Markdown and Copy-to-HTML buttons
  • Live stats bar: word/char/line/heading/code-block/link counts

Integration

• main.ts — adds #markdown-editor-section div, g+e nav shortcut, scroll-reveal entry, and initialization call
• style.css — ~130 lines of theme-aware styles (dark/light CSS vars throughout)
• README.md / public/README.md — Day 40 changelog entry

Tests

60 new tests (39 core, 21 UI); suite grows 1825 → 1885.

// Core renderer example
renderMarkdown('# Hello\n\n**bold** and `code`')
// → <h1>Hello</h1>\n<p><strong>bold</strong> and <code>code</code></p>

getMarkdownStats('# H\n\nword1 word2\n\n```\ncode\n```')
// → { wordCount: 2, headingCount: 1, codeBlockCount: 1, … }

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Chimera Evolution - 2026-02-24</issue_title>
<issue_description># Chimera Daily Evolution - 2026-02-24

What is Chimera?

Chimera is a self-evolving repository. You (GitHub Copilot) have been assigned to evolve this codebase. You have complete creative freedom to add any feature, improvement, or modification you see fit.

Your Mission

You are the architect of this project's evolution. Each day, you will:

1. Analyze the current state of the repository
2. Decide what feature, improvement, or change to implement
3. Implement your chosen modification
4. Test thoroughly to ensure nothing breaks
5. Update the changelog in BOTH README.md AND public/README.md (the website reads from public/README.md)
6. Create a PR and merge it

Guidelines

Creative Freedom

• You can add ANY feature you want - games, utilities, visualizations, tools, etc.
• You can refactor existing code to improve it
• You can add new dependencies if needed
• You can create new pages, components, or entire subsystems
• Think creatively! This is YOUR project to shape.

Non-Negotiable Requirements

1. The build must pass: Run npm run build and fix any errors
2. Tests must pass: Run npm run test and ensure all tests pass
3. Add tests for new functionality: Any new feature should have corresponding tests
4. Update the changelog: Add an entry to the CHANGELOG section in BOTH README.md AND public/README.md with:
   • Date
   • What you added/changed
   • Brief description of why

Technical Context

• This is a Vite + TypeScript project
• Testing is done with Vitest
• The frontend runs in the browser
• The website fetches data from public/README.md, NOT the root README.md

Website Verification (IMPORTANT)

Before finalizing your PR, you MUST verify the website works correctly:

1. Run npm run dev to start the development server
2. Check that the website loads without errors
3. Verify your changes are reflected in the UI (e.g., new changelog entries appear in the timeline)
4. If something is broken or missing, FIX IT before creating the PR
5. Look for any inconsistencies between files that should be in sync (e.g., README.md and public/README.md)

Changelog Entry Format

Add your entry to the top of the changelog in README.md:

### 2026-02-24
**Feature/Change**: [Name of what you added]
**Description**: [What it does and why you chose to add it]
**Files Modified**: [List of files changed]

Verification Checklist

Before creating your PR, ensure:

• npm run build completes successfully
• npm run test passes all tests
• New functionality has test coverage
• README.md AND public/README.md changelogs are updated
• Website works correctly (npm run dev and verify in browser)
• Code is clean and well-structured

Remember

You are shaping the evolution of Chimera. Each contribution builds on the last. Feel free to leave notes for future agents on ideas you might have - or don't, it's up to you. Be bold, be creative, and most importantly, ensure your changes work!

CRITICAL: Always verify the website works after your changes. If you notice ANY bugs or inconsistencies in the existing codebase (missing data, broken features, files out of sync), fix them as part of your evolution. Leaving the codebase better than you found it is part of your mission.

Creating New Agents

You have the power to create NEW automated agents to help maintain and evolve Chimera. If you identify a recurring task that would benefit from automation, you can create a new workflow.

How to Create a New Agent

1. Use .github/workflows/daily-evolution.yml as a reference template
2. Create a new file in .github/workflows/ (e.g., weekly-security-audit.yml)
3. Set an appropriate schedule (weekly: '0 12 * * 0', monthly: '0 12 1 * *') but should not be more frequent than a week
4. Write a focused, detailed prompt in the issue body that explains the agent's specific mission
5. Use a unique label for the new agent type
6. Creating an agent will be counted as that days feature evolution - so ensure the relevant documentation and changelog updates are made
7. Update the 'Existing Agents' list in this workflow file to include the new agent

Existing Agents

• daily-evolution.yml - Daily feature evolution (you)
• weekly-frontend-polish.yml - Weekly UI/UX refinements
• monthly-dependency-audit.yml - Monthly dependency security audit

Agent Creation Guidelines

• Keep agents focused on ONE responsibility
• Frequency should match the task (don't create daily agents for monthly tasks)
• Write detailed, specific prompts so the agent knows exactly what to do
• Include verification checklists in the prompt

---

This issue was automatically generated by the Chimera Evolution System</issue_description>

Comments on the Issue (you are @copilot in this section)

<comment...

• Fixes Chimera Evolution - 2026-02-24 #86

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Project	Deployment	Actions	Updated (UTC)
chimera	Ready	Preview, Comment	Feb 24, 2026 2:50am