feat(very_good_docs_site_jaspr): add Jaspr-powered docs site template

[marcossevilla]

Description

Closes #547

Adds very_good_docs_site_jaspr, an all-Dart documentation site template powered by Jaspr, as the counterpart to the Docusaurus-based very_good_docs_site. Generated sites carry no Node.js toolchain: no package.json, no npm, no JavaScript build config.

What the brick generates

• A landing page (hero, CTA, three feature pillars) and a docs layout built on jaspr_content's DocsLayout
• A sidebar derived from the filesystem, mirroring Docusaurus's { type: 'autogenerated' } behavior, ordered by sidebar_position frontmatter
• Light/dark theming through ColorTokens in one file (lib/src/colors.dart)
• Speculation Rules for hover-prefetch and pointer-down prerender, closing most of the gap with an SPA router
• Per-page "Edit this page" links, a GitHub navbar link, and a three-column site footer
• The usual scaffolding: issue templates, PR template, dependabot, CI workflow, MIT license

Registry wiring

Registered in mason.yaml, .release-please-config.json / .release-please-manifest.json (at 0.1.0), .github/dependabot.yaml, and bot_dependency_tightener.yaml, plus the three per-brick workflows (generate/verify, hooks, publish) and the active-brick list in AGENTS.md.

Notes for reviewers

Two workarounds are load-bearing and documented in place, rather than left for a future maintainer to rediscover:

• grammars/bash.json is a vendored TextMate grammar; grammars/yaml.json is hand-written. syntax_highlight_lite bundles only Dart, and a fence tagged with an unregistered language fails the build rather than degrading to plain text. The upstream YAML grammar relies on Oniguruma (?x) free-spacing regexes that Dart's RegExp cannot parse, so it throws FormatException: Invalid group. The rationale and the condition for removing the hand-written file live in its information_for_contributors block.
• build_web_compilers is imported by nothing but is what jaspr_cli compiles the client entrypoint through; a comment in pubspec.yaml records that.

The lib/main.*.options.dart files ship as the same stubs upstream Jaspr's own docs template ships. jaspr_builder declares them build_to: source and regenerates the real contents on every build, so committing a post-build snapshot would hard-code jaspr_content's private component surface behind a caret constraint.

Known follow-up, deliberately not in this PR

org_name currently serves two incompatible roles: LICENSE renders it as a copyright holder, while lib/main.server.dart splices it into https://github.com/{org_name}/{project_name}. No single value satisfies both. Splitting it into org_name plus a separate repo_owner changes the brick's variable surface, so it is worth its own discussion. This is inherited from very_good_docs_site, not introduced here.

Also left for a follow-up: component styles are mounted per-component via Document.head, so they are re-serialized per page and ship as duplicate <style> blocks in every page's head. Moving to @css plus styles: standalone would emit one build-time main.css, but it touches every component and warrants a separate change.

Verification

mason make from config.json, then against the generated output: dart format --set-exit-if-changed clean, dart analyze --fatal-infos --fatal-warnings clean, and jaspr build completing all 4 routes. Hook package formats, analyzes, and tests clean. cspell clean across the brick's .md and .dart files.

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore
• 🧪 Test

🤖 Generated with Claude Code