feat(presets): add pdflatex, tectonic, asciidoctor, and quarto presets (#30)

* feat(presets): add pdflatex preset

Adds a direct pdflatex preset for users who want single-pass
compilation without latexmk orchestration. Uses -file-line-error
for parseable diagnostics and reuses the existing parse_latexmk
error parser since both emit the same file:line: message format.

* feat(presets): add tectonic preset

Adds a tectonic preset for the modern Rust-based LaTeX engine, which
auto-downloads packages and requires no TeX installation. Reuses
parse_latexmk since tectonic emits the same file:line: message
diagnostic format.

* feat(presets): add asciidoctor preset

Adds an asciidoctor preset for AsciiDoc → HTML compilation with SSE
live-reload. Includes a parse_asciidoctor error parser handling the
"asciidoctor: SEVERITY: file: line N: message" format for both
ERROR and WARNING diagnostics.

* feat(presets): add quarto preset

Adds a quarto preset for .qmd scientific documents rendering to
self-contained HTML with SSE live-reload. Uses --embed-resources
to avoid a _files directory in the common case. No error_parser
since quarto errors are heterogeneous (mixed R/Python/pandoc output).

* refactor: apply stylua formatting to new preset code

lua/preview/presets.lua

@@ -93,6 +93,28 @@ local function parse_pandoc(output)
   return diagnostics
 end
 
+---@param output string
+---@return preview.Diagnostic[]
+local function parse_asciidoctor(output)
+  local diagnostics = {}
+  for line in output:gmatch('[^\r\n]+') do
+    local severity, _, lnum, msg = line:match('^asciidoctor: (%u+): (.+): line (%d+): (.+)$')
+    if lnum then
+      local sev = vim.diagnostic.severity.ERROR
+      if severity == 'WARNING' then
+        sev = vim.diagnostic.severity.WARN
+      end
+      table.insert(diagnostics, {
+        lnum = tonumber(lnum) - 1,
+        col = 0,
+        message = msg,
+        severity = sev,
+      })
+    end
+  end
+  return diagnostics
+end
+
 ---@type preview.ProviderConfig
 M.typst = {
   ft = 'typst',
@@ -137,6 +159,38 @@ M.latex = {
   open = true,
 }
 
+---@type preview.ProviderConfig
+M.pdflatex = {
+  ft = 'tex',
+  cmd = { 'pdflatex' },
+  args = function(ctx)
+    return { '-interaction=nonstopmode', '-file-line-error', '-synctex=1', ctx.file }
+  end,
+  output = function(ctx)
+    return (ctx.file:gsub('%.tex$', '.pdf'))
+  end,
+  error_parser = function(output)
+    return parse_latexmk(output)
+  end,
+  open = true,
+}
+
+---@type preview.ProviderConfig
+M.tectonic = {
+  ft = 'tex',
+  cmd = { 'tectonic' },
+  args = function(ctx)
+    return { ctx.file }
+  end,
+  output = function(ctx)
+    return (ctx.file:gsub('%.tex$', '.pdf'))
+  end,
+  error_parser = function(output)
+    return parse_latexmk(output)
+  end,
+  open = true,
+}
+
 ---@type preview.ProviderConfig
 M.markdown = {
   ft = 'markdown',
@@ -187,4 +241,42 @@ M.github = {
   reload = true,
 }
 
+---@type preview.ProviderConfig
+M.asciidoctor = {
+  ft = 'asciidoc',
+  cmd = { 'asciidoctor' },
+  args = function(ctx)
+    return { ctx.file, '-o', ctx.output }
+  end,
+  output = function(ctx)
+    return (ctx.file:gsub('%.adoc$', '.html'))
+  end,
+  error_parser = function(output)
+    return parse_asciidoctor(output)
+  end,
+  clean = function(ctx)
+    return { 'rm', '-f', (ctx.file:gsub('%.adoc$', '.html')) }
+  end,
+  open = true,
+  reload = true,
+}
+
+---@type preview.ProviderConfig
+M.quarto = {
+  ft = 'quarto',
+  cmd = { 'quarto' },
+  args = function(ctx)
+    return { 'render', ctx.file, '--to', 'html', '--embed-resources' }
+  end,
+  output = function(ctx)
+    return (ctx.file:gsub('%.qmd$', '.html'))
+  end,
+  clean = function(ctx)
+    local base = ctx.file:gsub('%.qmd$', '')
+    return { 'rm', '-rf', base .. '.html', base .. '_files' }
+  end,
+  open = true,
+  reload = true,
+}
+
 return M