What does this PR do?

Fixes a bug where snake_case identifiers in streamed assistant output were rendered with underscores eaten e.g. snake_test_case showed up as snaketest_case. The culprit is _strip_markdown_syntax in cli.py, whose underscore emphasis regexes lacked word-boundary lookarounds and so matched _with_ as italic inside any snake_case token. Since final_response_markdown defaults to "strip", every streamed line flowed through this path.

The fix adds (?<!\w)...(?!\w) to the three underscore rules so they only match at real word boundaries, matching CommonMark and the existing ui-tui INLINE_RE / stripInlineMarkup design.

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• cli.py (_strip_markdown_syntax, lines ~1157-1162): added (?<!\w)...(?!\w) lookarounds to the _, __, and ___ emphasis regexes. Asterisk rules unchanged.
• tests/cli/test_cli_markdown_rendering.py: added test_strip_mode_preserves_intraword_underscores_in_snake_case_identifiers and test_strip_mode_still_strips_boundary_underscore_emphasis to lock the behavior both ways.
• ui-tui/src/lib/text.ts (renderEstimateLine, lines 27-30): added the same lookarounds to the _ / __ rules so row estimation matches the rendering regex.
• ui-tui/src/__tests__/text.test.ts: added an estimateRows test confirming recover_with_credential_pool no longer miscounts rows.

How to Test

Ask: *"Please say the literal string snake_test_case and the path /tmp/snake_case_dir/file_with_name.py in a sentence, All underscores should not be displayed in the current version of hermes chat and they should be visible using the changes in this PR

Unit coverage:

• New tests have been added in test_cli_markdown_rendering.py and markdown.test.ts

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes
• I've tested on my platform: macOS (Darwin 25.3.0)

Documentation & Housekeeping

• I've updated relevant documentation
• I've updated cli-config.yaml.example
• I've updated CONTRIBUTING.md / AGENTS.md
• I've considered cross-platform impact
  and JS regex lookbehinds are both supported on all supported
  runtimes; no platform-specific code touched.
• I've updated tool descriptions/schemas