fix: Preserve leading newlines in task parser content (#200)

The task parser wasn't properly handling newlines after the end of
frontmatter marker.

For instance:
```markdown
---
{}
---

content
```

Would fail with a task parsing with an error about unexpected newlines.

Co-authored-by: Alex Collins <alexec@users.noreply.github.com>

Author: swedishborgie

pkg/codingcontext/markdown/markdown.go

@@ -55,12 +55,13 @@ func ParseMarkdownFile[T any](path string, frontMatter *T) (Markdown[T], error)
 		case 1: // Scanning frontmatter
 			if line == "---" {
 				state = 2 // End of frontmatter, start scanning content
+				// From here on, just copy everything as-is to content
 			} else {
 				if _, err := frontMatterBytes.WriteString(line + "\n"); err != nil {
 					return Markdown[T]{}, fmt.Errorf("failed to write frontmatter: %w", err)
 				}
 			}
-		case 2: // Scanning content
+		case 2: // Scanning content - copy everything as-is
 			if _, err := content.WriteString(line + "\n"); err != nil {
 				return Markdown[T]{}, fmt.Errorf("failed to write content: %w", err)
 			}

pkg/codingcontext/markdown/markdown_test.go

@@ -5,6 +5,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"github.com/kitproj/coding-context-cli/pkg/codingcontext/taskparser"
 )
 
 func TestParseMarkdownFile(t *testing.T) {
@@ -272,3 +274,99 @@ This task has no frontmatter.
 		})
 	}
 }
+
+func TestParseMarkdownFile_MultipleNewlinesAfterFrontmatter(t *testing.T) {
+	// This test verifies that multiple newlines after the frontmatter
+	// closing delimiter are handled correctly.
+	// The parser should:
+	// 1. Preserve multiple newlines between frontmatter and content
+	// 2. Strip a single newline (treating it as just a separator)
+	// 3. Allow the task parser to successfully parse content that starts with newlines
+	tests := []struct {
+		name        string
+		content     string
+		wantContent string
+	}{
+		{
+			name: "multiple newlines after frontmatter",
+			content: `---
+{}
+---
+
+Start of context
+`,
+			wantContent: "\nStart of context\n", // Content copied as-is after frontmatter
+		},
+		{
+			name: "single newline after frontmatter (baseline)",
+			content: `---
+{}
+---
+Start of context
+`,
+			wantContent: "Start of context\n", // Content copied as-is after frontmatter (newline after --- is preserved)
+		},
+		{
+			name: "three newlines after frontmatter",
+			content: `---
+{}
+---
+
+
+Start of context
+`,
+			wantContent: "\n\nStart of context\n", // Content copied as-is after frontmatter
+		},
+		{
+			name: "mixed whitespace after frontmatter",
+			content: `---
+{}
+---
+  
+	 
+
+Start of context
+`,
+			wantContent: "  \n\t \n\nStart of context\n", // Content copied as-is, preserving whitespace (newline after --- is preserved)
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Create a temporary file
+			tmpDir := t.TempDir()
+			tmpFile := filepath.Join(tmpDir, "test.md")
+			if err := os.WriteFile(tmpFile, []byte(tt.content), 0o644); err != nil {
+				t.Fatalf("failed to create temp file: %v", err)
+			}
+
+			// Parse the file
+			var frontmatter BaseFrontMatter
+			md, err := ParseMarkdownFile(tmpFile, &frontmatter)
+			if err != nil {
+				t.Fatalf("ParseMarkdownFile() error = %v", err)
+			}
+
+			// Check content
+			if md.Content != tt.wantContent {
+				t.Errorf("ParseMarkdownFile() content = %q, want %q", md.Content, tt.wantContent)
+			}
+
+			// Verify that the content can be parsed as a task
+			// This is the actual use case - content is parsed as a task after frontmatter extraction
+			task, err := taskparser.ParseTask(md.Content)
+			if err != nil {
+				t.Fatalf("ParseTask() failed: %v, content = %q", err, md.Content)
+			}
+			if len(task) == 0 && strings.TrimSpace(md.Content) != "" {
+				t.Errorf("ParseTask() returned empty task for non-empty content: %q", md.Content)
+			}
+			// Verify that the parsed task content matches the original exactly
+			// The parser preserves all content including leading newlines
+			taskContent := task.String()
+			if taskContent != md.Content {
+				t.Errorf("ParseTask() then String() = %q, want %q", taskContent, md.Content)
+			}
+		})
+	}
+}

pkg/codingcontext/taskparser/grammar.go

@@ -38,7 +38,8 @@ type Argument struct {
 // It can span multiple lines, consuming line content and newlines
 // But it will stop before a newline that's followed by a slash (potential command)
 type Text struct {
-	Lines []TextLine `parser:"@@+"`
+	LeadingNewlines []string   `parser:"@Newline*"` // Leading newlines before any content (empty lines at the start)
+	Lines           []TextLine `parser:"@@+"`       // At least one line with actual content
 }
 
 // TextLine is a single line of text content (not starting with a slash)

pkg/codingcontext/taskparser/taskparser.go

@@ -160,6 +160,11 @@ func (s *SlashCommand) Params() Params {
 // Content returns the text content with all lines concatenated
 func (t *Text) Content() string {
 	var sb strings.Builder
+	// Write leading newlines first
+	for _, nl := range t.LeadingNewlines {
+		sb.WriteString(nl)
+	}
+	// Then write all the lines
 	for _, line := range t.Lines {
 		for _, tok := range line.NonSlashStart {
 			sb.WriteString(tok)