add snonux static microblog generator

Full Go implementation with:
- txt/md/image/audio input processing, URL auto-linking in .txt files
- Paginated HTML output with Atom feed
- 11 visual themes: neon, terminal, synthwave, minimal, brutalist, paper,
  aurora, matrix, ocean, retro, glass (selectable via --theme flag)
- Keyboard navigation (j/k/arrows, Enter modal, h/l page nav)
- Shared nav templates (navhints, navmodal, navscript) across all themes
- Magefile build automation; integration test suite covering all themes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/internal/processor/txt.go b/internal/processor/txt.go
new file mode 100644
index 0000000..8381271
--- /dev/null
+++ b/internal/processor/txt.go
@@ -0,0 +1,103 @@
+package processor
+
+import (
+	"fmt"
+	"html"
+	"os"
+	"regexp"
+	"strings"
+)
+
+// urlPattern matches http/https URLs in plain text.
+// Trailing sentence punctuation is stripped separately by stripURLTrailing.
+var urlPattern = regexp.MustCompile(`https?://\S+`)
+
+// processTxt reads a plain-text file and wraps each non-empty paragraph in <p> tags.
+// URLs are automatically converted to clickable <a> links.
+// Non-URL text is HTML-escaped to prevent XSS.
+func processTxt(path string) (string, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("read txt %s: %w", path, err)
+	}
+
+	raw := strings.TrimSpace(string(data))
+	if raw == "" {
+		return "<p></p>", nil
+	}
+
+	// Split on blank lines to get logical paragraphs.
+	paragraphs := strings.Split(raw, "\n\n")
+	var sb strings.Builder
+
+	for _, para := range paragraphs {
+		trimmed := strings.TrimSpace(para)
+		if trimmed == "" {
+			continue
+		}
+		fmt.Fprintf(&sb, "<p>%s</p>\n", formatParagraph(trimmed))
+	}
+
+	return sb.String(), nil
+}
+
+// formatParagraph formats a single paragraph: auto-links URLs, escapes non-URL
+// text, and converts single newlines to <br> line breaks.
+func formatParagraph(para string) string {
+	lines := strings.Split(para, "\n")
+	formatted := make([]string, 0, len(lines))
+
+	for _, line := range lines {
+		if t := strings.TrimSpace(line); t != "" {
+			formatted = append(formatted, autolinkLine(t))
+		}
+	}
+
+	return strings.Join(formatted, "<br>\n")
+}
+
+// autolinkLine escapes non-URL text and wraps detected URLs in <a> tags.
+// Opens in a new tab with rel="noopener noreferrer" for security.
+func autolinkLine(line string) string {
+	locs := urlPattern.FindAllStringIndex(line, -1)
+	if len(locs) == 0 {
+		return html.EscapeString(line)
+	}
+
+	var sb strings.Builder
+	prev := 0
+
+	for _, loc := range locs {
+		sb.WriteString(html.EscapeString(line[prev:loc[0]]))
+
+		rawURL := line[loc[0]:loc[1]]
+		cleanURL := stripURLTrailing(rawURL)
+		trailing := rawURL[len(cleanURL):]
+
+		fmt.Fprintf(&sb, `<a href="%s" target="_blank" rel="noopener noreferrer">%s</a>`,
+			html.EscapeString(cleanURL), html.EscapeString(cleanURL))
+
+		if trailing != "" {
+			sb.WriteString(html.EscapeString(trailing))
+		}
+
+		prev = loc[1]
+	}
+
+	sb.WriteString(html.EscapeString(line[prev:]))
+
+	return sb.String()
+}
+
+// stripURLTrailing removes common sentence-ending punctuation from the end of a
+// URL match. These characters are valid in URLs but almost never appear there
+// at the end in prose (e.g. "Visit https://foo.com." — the "." ends the sentence).
+func stripURLTrailing(u string) string {
+	const cutset = ".,;:!?\"')>]}"
+
+	for len(u) > 0 && strings.ContainsRune(cutset, rune(u[len(u)-1])) {
+		u = u[:len(u)-1]
+	}
+
+	return u
+}