fix: parse -o flag correctly to resolve output filename

Fix bug where -o flag value was read as pointer instead of string value,
causing memory addresses to be printed and output path to resolve to ".xlsx".

AGENTS.md

@@ -0,0 +1,73 @@
+# Agent Instructions
+
+## Plans
+
+- Make the plan extremely concise. Sacrifice grammar for the sake of concision.
+- At the end of each plan, give me a list of unresolved questions to answer, if any.
+
+## Issue Tracking
+
+This project uses **br** (beads_rust) for issue tracking and **bv** (beads_viewer) for triage/prioritization. Issues are stored in `.beads/` and tracked in git.
+
+### Tool Roles
+
+| Tool | Role | Key Commands |
+|------|------|--------------|
+| `br` | Issue management (CRUD) | `br ready`, `br show`, `br update`, `br close`, `br sync` |
+| `bv` | Triage & prioritization | `bv --robot-triage` |
+
+### Quick Reference
+
+```bash
+br ready              # Find available work
+br show <id>          # View issue details
+br update <id> --status in_progress  # Claim work
+br close <id>         # Complete work
+br sync               # Sync with git
+```
+
+### What to work on next?
+
+```bash
+bv --robot-triage     # AI-powered recommendation for next issue (preferred)
+br ready              # Fallback: plain list of unblocked issues
+```
+
+> **Warning:** bare `bv` (without flags) launches an interactive TUI that blocks the session. Always use `bv --robot-triage` or other non-interactive flags in automated contexts.
+
+### Key Concepts
+
+- **Dependencies**: Issues can block other issues. `br ready` shows only unblocked work.
+- **Priority**: P0=critical, P1=high, P2=medium, P3=low, P4=backlog (use numbers 0-4, not words)
+- **Types**: task, bug, feature, epic, chore, docs, question
+- **Blocking**: `br dep add <issue> <depends-on>` to add dependencies
+
+
+### Creating issues
+
+You might be tasked with creating a new issue or you discover new tasks by yourself. Use the `/create-single-issue` command accordingly the create a new issue.
+
+## Main Workflow
+
+### Work on issue
+
+You are tasked by the operator to work on an issue.
+It's either a specific issue (`/start-issue <id>`) or the *next* issue (`/start-next-issue`).
+The command tells you to open the issue, enter plan mode and then implement the plan.
+The command tells you explicitly *NOT* to: close the issue, commit or push anything (because this is subject to `/finish-issue`).
+
+### Operator tests manually
+
+After finishing the implementation the operator tests the solution.
+
+### Finish issue
+
+After testing you are tasked by the operator to finish the issue (`/finish-issue`).
+You close the issue and create a commit.
+
+## Release Workflow
+
+Once in a while the operator uses these commands:
+
+- `/tag-version` - you create a new version using the `git tag` mechanism
+- `/update-changelog` - you update the CHANGELOG.md according to the changes of the last version

main.go

@@ -26,10 +26,13 @@ func main() {
 		os.Exit(1)
 	}
 
-	fmt.Println(sep)
-	fmt.Println(enc)
-	fmt.Println(out)
+	if err := run(files, *out, *sep, *enc); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
 
+func run(files []string, out, sep, enc string) error {
 	xlsx := excelize.NewFile()
 	firstSheet := true
 
@@ -49,11 +52,11 @@ func main() {
 		defer f.Close()
 
 		var reader io.Reader = f
-		if *enc == "windows1252" {
+		if enc == "windows1252" {
 			reader = transform.NewReader(f, charmap.Windows1252.NewDecoder())
 		}
 
-		delimiter := detectDelimiter(path, *sep)
+		delimiter := detectDelimiter(path, sep)
 
 		csvReader := csv.NewReader(reader)
 		csvReader.Comma = delimiter
@@ -85,12 +88,11 @@ func main() {
 		fmt.Printf("✓ %s → Reiter \"%s\" (%d Zeilen)\n", path, sheetName, row-1)
 	}
 
-	if err := xlsx.SaveAs(*out); err != nil {
-		fmt.Fprintf(os.Stderr, "Fehler beim Speichern: %v\n", err)
-		os.Exit(1)
+	if err := xlsx.SaveAs(out); err != nil {
+		return fmt.Errorf("Fehler beim Speichern: %w", err)
 	}
-	fmt.Printf("✅ Gespeichert: %s\n", *out)
-
+	fmt.Printf("✅ Gespeichert: %s\n", out)
+	return nil
 }
 
 func detectDelimiter(path, hint string) rune {

main_test.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/xuri/excelize/v2"
+)
+
+func writeTempCSV(t *testing.T, dir, name, content string) string {
+	t.Helper()
+	path := filepath.Join(dir, name)
+	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
+		t.Fatalf("WriteFile: %v", err)
+	}
+	return path
+}
+
+func TestRun_OutputPath(t *testing.T) {
+	dir := t.TempDir()
+	csv := writeTempCSV(t, dir, "data.csv", "name,age\nAlice,30\nBob,25\n")
+	out := filepath.Join(dir, "result.xlsx")
+
+	if err := run([]string{csv}, out, "auto", "utf8"); err != nil {
+		t.Fatalf("run() error: %v", err)
+	}
+
+	if _, err := os.Stat(out); os.IsNotExist(err) {
+		t.Fatalf("output file not created: %s", out)
+	}
+}
+
+func TestRun_SheetContent(t *testing.T) {
+	dir := t.TempDir()
+	csv := writeTempCSV(t, dir, "sheet1.csv", "col1;col2\nfoo;bar\n")
+	out := filepath.Join(dir, "out.xlsx")
+
+	if err := run([]string{csv}, out, ";", "utf8"); err != nil {
+		t.Fatalf("run() error: %v", err)
+	}
+
+	f, err := excelize.OpenFile(out)
+	if err != nil {
+		t.Fatalf("OpenFile: %v", err)
+	}
+
+	val, err := f.GetCellValue("sheet1", "A1")
+	if err != nil {
+		t.Fatalf("GetCellValue: %v", err)
+	}
+	if val != "col1" {
+		t.Errorf("A1 = %q, want %q", val, "col1")
+	}
+
+	val, err = f.GetCellValue("sheet1", "B2")
+	if err != nil {
+		t.Fatalf("GetCellValue: %v", err)
+	}
+	if val != "bar" {
+		t.Errorf("B2 = %q, want %q", val, "bar")
+	}
+}
+
+func TestRun_MultipleSheets(t *testing.T) {
+	dir := t.TempDir()
+	csv1 := writeTempCSV(t, dir, "alpha.csv", "x\n1\n")
+	csv2 := writeTempCSV(t, dir, "beta.csv", "y\n2\n")
+	out := filepath.Join(dir, "multi.xlsx")
+
+	if err := run([]string{csv1, csv2}, out, "auto", "utf8"); err != nil {
+		t.Fatalf("run() error: %v", err)
+	}
+
+	f, err := excelize.OpenFile(out)
+	if err != nil {
+		t.Fatalf("OpenFile: %v", err)
+	}
+
+	sheets := f.GetSheetList()
+	if len(sheets) != 2 {
+		t.Fatalf("got %d sheets, want 2", len(sheets))
+	}
+	if sheets[0] != "alpha" || sheets[1] != "beta" {
+		t.Errorf("sheets = %v, want [alpha beta]", sheets)
+	}
+}
+
+func TestRun_CustomOutputFilename(t *testing.T) {
+	dir := t.TempDir()
+	csv := writeTempCSV(t, dir, "input.csv", "a,b\n1,2\n")
+	out := filepath.Join(dir, "custom_name.xlsx")
+
+	if err := run([]string{csv}, out, ",", "utf8"); err != nil {
+		t.Fatalf("run() error: %v", err)
+	}
+
+	if _, err := os.Stat(out); os.IsNotExist(err) {
+		t.Fatalf("expected output at %s, not found", out)
+	}
+	// ensure default name was NOT created
+	defaultOut := filepath.Join(dir, "output.xlsx")
+	if _, err := os.Stat(defaultOut); !os.IsNotExist(err) {
+		t.Errorf("unexpected file created at %s", defaultOut)
+	}
+}