fix: resolve all YAML template literal issues in merge-bot workflow

[vilsonrodrigues]

Summary

This PR completely fixes all YAML syntax errors in the merge-bot workflow by replacing problematic template literals with array-based string construction.

Problem

After PR #21 was merged, the workflow still has multiple YAML parsing errors caused by template literals with backticks inside YAML string literals. GitHub Actions fails to parse the workflow file at multiple locations:

• Line 420-424: Fork PR message with code block
• Line 613: Success message with inline backticks
• Line 635-645: Failure message with code block

Error pattern:

yaml.scanner.ScannerError: while scanning a simple key
could not find expected ':'

Root Cause

YAML parser struggles with:

• Template literals containing escaped backticks: \``bash`
• Multiline strings with complex interpolations
• Nested backticks in template literals inside YAML script: blocks

Solution

Replace all problematic template literals with array-based string construction:

Before (❌ Causes YAML errors):

body: `Message here
\`\`\`bash
git fetch upstream ${pr.base.ref}
\`\`\`
More text`

After (✅ Clean and valid):

const message = [
  'Message here',
  '```bash',
  `git fetch upstream ${baseBranch}`,
  '```',
  'More text'
].join('\n');

body: message

Changes Made

1. Fork PR message (lines 412-425): Array-based construction
2. Success message (line 607): Extract to variable before use
3. Failure message (lines 631-643): Array-based construction

Validation

✅ Python YAML parser: Validates successfully
✅ Node.js syntax check: JavaScript is valid
✅ act (GitHub Actions local runner): Workflow parses correctly

All three validation methods pass!

Testing

After merge, test with PR #20:

1. Comment /update on PR docs: enhance module docstring (TEST PR for /update command) #20
2. Verify the bot can now run successfully
3. Check that messages format correctly with code blocks

Related

• Fixes issues introduced in PR fix: improve mergebot /update command with better fork handling and checkout #19
• Supersedes PR fix: resolve YAML syntax error in merge-bot workflow #21 (partial fix)
• Enables testing of /update command on PR docs: enhance module docstring (TEST PR for /update command) #20

🤖 Generated with Claude Code

[vilsonrodrigues]

/merge