feat: add PDF/EPUB import functionality

- Add ImportTask/ImportResult types to domain.go
- Add TypeImportBook to asynqqueue for task routing
- Add CreateImportTask to producer and storage layers
- Add ClaimNextImportTask/FinishImportTask to Consumer
- Add import task handling to runner (polling + Asynq handler)
- Add BookImporter interface to bookstore for PDF/EPUB parsing
- Add backend API endpoints: POST/GET /api/admin/import
- Add SvelteKit UI at /admin/import with task list
- Add nav link in admin layout

Note: PDF/EPUB parsing is a placeholder - needs external library integration.

backend/cmd/pdf-to-chapters/main.go

@@ -0,0 +1,165 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"strings"
+
+	"github.com/ledongthuc/pdf"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println("Usage: pdf-to-chapters <input.pdf>")
+		os.Exit(1)
+	}
+
+	inputPath := os.Args[1]
+
+	if err := processPDF(inputPath); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func processPDF(inputPath string) error {
+	pdf.DebugOn = false
+
+	f, r, err := pdf.Open(inputPath)
+	if err != nil {
+		return fmt.Errorf("failed to open PDF: %w", err)
+	}
+	defer f.Close()
+
+	totalPages := r.NumPage()
+	fmt.Printf("Processing PDF with %d pages\n", totalPages)
+
+	var chapters []Chapter
+	var currentChapter *Chapter
+
+	chapterPattern := regexp.MustCompile(`The Eminence in Shadow\s+(\d+)\s*-\s*(\d+)`)
+
+	for i := 1; i <= totalPages; i++ {
+		page := r.Page(i)
+		if err := page.IsValid(); err != nil {
+			log.Printf("Warning: page %d not valid: %v", i, err)
+			continue
+		}
+
+		text, err := page.GetPlainText(nil)
+		if err != nil {
+			log.Printf("Warning: failed to extract text from page %d: %v", i, err)
+			continue
+		}
+
+		// Check for chapter header on this page
+		matches := chapterPattern.FindStringSubmatch(text)
+		if matches != nil {
+			// Start new chapter
+			if currentChapter != nil && len(currentChapter.Content) > 0 {
+				chapters = append(chapters, *currentChapter)
+			}
+
+			chapterNum := matches[1]
+			currentChapter = &Chapter{
+				Number:    chapterNum,
+				StartPage: i,
+				Content:   text,
+			}
+			continue
+		}
+
+		// Append to current chapter
+		if currentChapter != nil {
+			currentChapter.Content += "\n" + text
+		}
+	}
+
+	// Don't forget last chapter
+	if currentChapter != nil && len(currentChapter.Content) > 0 {
+		chapters = append(chapters, *currentChapter)
+	}
+
+	// Print chapter info
+	fmt.Printf("Total chapters found: %d\n", len(chapters))
+	for _, ch := range chapters {
+		preview := strings.TrimSpace(ch.Content)
+		if len(preview) > 200 {
+			preview = preview[:200] + "..."
+		}
+		fmt.Printf("Chapter %s (page %d): %s\n", ch.Number, ch.StartPage, preview)
+	}
+
+	// Write output file
+	return writeOutput(chapters, inputPath)
+}
+
+type Chapter struct {
+	Number    string
+	StartPage int
+	Content   string
+}
+
+func writeOutput(chapters []Chapter, inputPath string) error {
+	baseName := strings.TrimSuffix(inputPath, ".pdf")
+	outPath := baseName + "_chapters.txt"
+
+	f, err := os.Create(outPath)
+	if err != nil {
+		return fmt.Errorf("failed to create output: %w", err)
+	}
+	defer f.Close()
+
+	for i, ch := range chapters {
+		if i > 0 {
+			fmt.Fprintln(f)
+		}
+		fmt.Fprintf(f, "## Chapter %s\n\n", ch.Number)
+
+		// Split content into paragraphs
+		paragraphs := splitIntoParagraphs(ch.Content)
+		for _, para := range paragraphs {
+			trimmed := strings.TrimSpace(para)
+			if len(trimmed) > 0 {
+				fmt.Fprintln(f, trimmed)
+				fmt.Fprintln(f)
+			}
+		}
+	}
+
+	fmt.Printf("\nOutput written to: %s\n", outPath)
+	return nil
+}
+
+func splitIntoParagraphs(text string) []string {
+	lines := strings.Split(text, "\n")
+	var paragraphs []string
+	var currentPara strings.Builder
+
+	for _, line := range lines {
+		trimmed := strings.TrimSpace(line)
+		// Skip empty lines and very short lines (likely headers/page numbers)
+		if len(trimmed) == 0 {
+			if currentPara.Len() > 0 {
+				paragraphs = append(paragraphs, currentPara.String())
+				currentPara.Reset()
+			}
+			continue
+		}
+		if len(trimmed) < 3 {
+			continue
+		}
+
+		if currentPara.Len() > 0 {
+			currentPara.WriteString(" ")
+		}
+		currentPara.WriteString(trimmed)
+	}
+
+	if currentPara.Len() > 0 {
+		paragraphs = append(paragraphs, currentPara.String())
+	}
+
+	return paragraphs
+}

backend/go.mod

@@ -3,6 +3,7 @@ module github.com/libnovel/backend
 go 1.26.1
 
 require (
+	github.com/ledongthuc/pdf v0.0.0-20241014091450-14fc3c58b12d
 	github.com/minio/minio-go/v7 v7.0.98
 	golang.org/x/net v0.51.0
 )