Migrate templates to Jet v6 with reusable components

[retlehs]

Summary

• Migrate all templates from Go's html/template to Jet v6 (CloudyKit/jet/v6) for first-class parameterized blocks, template inheritance, and C-like expressions
• Add components.html with four reusable Jet blocks: shell, notice, input, pagination
• Replace ~110 lines of duplicated HTML across docs, compare, detail, index, and untagged templates
• Simplify Go-side template loading: single *jet.Set replaces pre-parsed templateSet with 11 template combinations
• Add buildPagination() helper for pre-computing pagination URLs passed to the pagination component

Why Jet?

html/template has no parameterized components — the previous approach required dict helper functions and trustedHTML workarounds to pass props to shared template blocks. Jet's block/yield with named parameters and default values, plus yield content for slot-based composition, makes reusable components natural:

{{yield shell(command="composer require wp-plugin/woocommerce", variant="amber", class="mb-4")}}

{{yield notice(variant="warning", class="mb-6") content}}
  Your warning content with <strong>HTML</strong> here.
{{end}}

Components

Component	Block signature	Replaces
shell	shell(command, variant="default", class="")	16 duplicated copy-to-clipboard command boxes
notice	notice(variant="warning", class="") + yield content	6 duplicated alert/warning boxes
input	input(icon, name, value, placeholder, type, showShortcut, id, autocomplete)	Duplicated search/filter inputs
pagination	pagination(pager, class="")	Duplicated pagination controls in 2 partials

Test plan

• Verify all pages render correctly: index, detail, docs, compare, wordpress-core, untagged, status, admin/logs, 404
• Verify shell command blocks render and copy-to-clipboard works
• Verify notice components render with correct variant styling
• Verify search input with / shortcut works on index and untagged pages
• Verify author input with autocomplete/clear button works on untagged page
• Verify HTMX partial loading works (search filtering, pagination on index and untagged)
• Verify pagination renders correctly with page range ellipsis

🤖 Generated with Claude Code