Replace Torchlight with native Rouge syntax highlighting

[Copilot]

This PR removes the Torchlight API dependency and migrates syntax highlighting to Bridgetown’s built-in Rouge pipeline. The goal is to keep code rendering quality while eliminating token/config/CI coupling to an external highlighter.

• Highlighting pipeline migration

  • Switched bridgetown.config.yml from highlighter: "" to highlighter: rouge.
  • Removed Torchlight runtime integration (plugins/builders/torchlight.rb, torchlight.config.cjs).
  • Removed post-level Torchlight opt-in (src/_posts/_defaults.yml).

• Code block styling parity on Rouge output

  • Replaced pre.torchlight/fallback styling with Rouge-aware selectors:
    • .highlighter-rouge .highlight pre.highlight
    • pre:not(.highlight) fallback
  • Added token-level Rouge class styling (.k, .s*, .c*, .na/.nf/.nc, .gd/.gi) using existing design tokens.

• Dependency and secret surface cleanup

  • Removed @torchlight-api/torchlight-cli from package.json and lockfile.
  • Removed TORCHLIGHT_TOKEN usage from CI workflows and fnox.toml.
  • Removed .torchlight-cache/ ignore entry.

• Documentation and operational updates

  • Updated README, AGENTS, design-system docs, runbooks, and mise.toml comments to reflect Rouge-first behavior and remove Torchlight/token rotation references.
  • Updated OG builder comments that referenced Torchlight ordering.

# bridgetown.config.yml
highlighter: rouge

[andrewmcodes]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved and merged origin/main into this PR branch, fixing the conflicts in README.md, docs/design-system.md, and docs/runbooks.md in commit f416efa.

[github-actions]

Preview: https://pr-568-copilot-explore-dropping-torchlig-andrewm-codes.andrewmcodes.workers.dev

[andrewmcodes]

@copilot your syntax highlighting theme should be similar to OneDark Pro instead of this custom bullshit you did. I need WAY more colors in my syntax highlighting.

[Copilot]

@copilot your syntax highlighting theme should be similar to OneDark Pro instead of this custom bullshit you did. I need WAY more colors in my syntax highlighting.

Updated in 81c0284 with a OneDark Pro-like Rouge theme and expanded token coverage so syntax highlighting uses many more distinct colors.

[andrewmcodes]

@copilot the new theme is way better, but can we tweak it just slightly to better fit in with the website theme?

[Copilot]

@copilot the new theme is way better, but can we tweak it just slightly to better fit in with the website theme?

Done in 7aab311 with a subtle palette tune so the OneDark-like Rouge theme blends better with the site (mint/sage-aligned accents and slightly adjusted base code block tones).

[andrewmcodes]

None of the torchlight cache files should be added so keep the gitignore entry

[andrewmcodes]

@copilot there are torchlight-cache/* files in the diff that shouldn't be.

[Copilot]

@copilot there are torchlight-cache/* files in the diff that shouldn't be.

Fixed in 9fdd2b1: removed tracked .torchlight-cache/* files from the branch and restored .torchlight-cache/ in .gitignore.