feat: display friendly names for memory files (closes #177)

The memory file list now shows human-readable titles instead of raw
filenames wherever possible.

- Rust: adds `MemoryFileInfo { path, heading }` and updates
  `MemoryFilesResponse` to use `Vec<MemoryFileInfo>`; adds
  `extract_first_heading()` helper that scans the first `# Heading`
  from a file's content; both `list_memory_files_native` and
  `list_memory_files_via_wsl` now read each file and populate the
  heading field; raw filename remains available as a fallback
- Frontend: updates `MemoryBrowserPanel.svelte` to use the richer type;
  adds `getDisplayName()` which returns the heading or falls back to the
  raw filename; file buttons use the display name with the raw filename
  as a tooltip; the viewer header also shows the display name with the
  filename shown as a subtitle when a heading is present
- Tests: 8 new Rust unit tests for `extract_first_heading` (happy path,
  edge cases, empty content, whitespace); 12 new TypeScript tests for
  `getFileName` and `getDisplayName` mirrored from the component

src-tauri/src/commands.rs

@@ -862,6 +862,26 @@ pub async fn read_file_content(path: String) -> Result<String, String> {
         .map_err(|e| format!("Failed to read file: {}", e))
 }
 
+/// Read the first `# Heading` from a WSL file path (for Windows).
+/// Returns `None` if the file cannot be read or has no top-level heading.
+#[cfg(target_os = "windows")]
+fn read_wsl_file_first_heading(path: &str) -> Option<String> {
+    use std::process::Command;
+
+    let output = Command::new("wsl")
+        .hide_window()
+        .args(["-e", "bash", "-c", &format!("head -20 '{}'", path)])
+        .output()
+        .ok()?;
+
+    if !output.status.success() {
+        return None;
+    }
+
+    let content = String::from_utf8_lossy(&output.stdout);
+    extract_first_heading(&content)
+}
+
 /// Read file content via WSL (for Windows with WSL paths)
 #[allow(dead_code)]
 async fn read_file_via_wsl(path: &str) -> Result<String, String> {
@@ -1353,9 +1373,29 @@ pub async fn close_application(app_handle: AppHandle) -> Result<(), String> {
     Ok(())
 }
 
+#[derive(serde::Serialize)]
+pub struct MemoryFileInfo {
+    pub path: String,
+    pub heading: Option<String>,
+}
+
 #[derive(serde::Serialize)]
 pub struct MemoryFilesResponse {
-    pub files: Vec<String>,
+    pub files: Vec<MemoryFileInfo>,
+}
+
+/// Extract the first `# Heading` from a string of file content.
+fn extract_first_heading(content: &str) -> Option<String> {
+    content.lines().find_map(|line| {
+        let trimmed = line.trim();
+        if let Some(rest) = trimmed.strip_prefix("# ") {
+            let heading = rest.trim().to_string();
+            if !heading.is_empty() {
+                return Some(heading);
+            }
+        }
+        None
+    })
 }
 
 #[tauri::command]
@@ -1398,12 +1438,19 @@ async fn list_memory_files_via_wsl() -> Result<MemoryFilesResponse, String> {
     }
 
     let stdout = String::from_utf8_lossy(&output.stdout);
-    let files: Vec<String> = stdout
+    let paths: Vec<String> = stdout
         .lines()
         .filter(|line| !line.trim().is_empty())
         .map(|line| line.trim().to_string())
         .collect();
 
+    // Read first heading from each file via WSL
+    let mut files = Vec::new();
+    for path in paths {
+        let heading = read_wsl_file_first_heading(&path);
+        files.push(MemoryFileInfo { path, heading });
+    }
+
     Ok(MemoryFilesResponse { files })
 }
 
@@ -1425,10 +1472,13 @@ async fn list_memory_files_native() -> Result<MemoryFilesResponse, String> {
         return Ok(MemoryFilesResponse { files: Vec::new() });
     }
 
-    let mut memory_files = Vec::new();
+    let mut memory_paths = Vec::new();
 
     // Recursively find all memory directories
-    fn find_memory_files(dir: &std::path::Path, files: &mut Vec<String>) -> std::io::Result<()> {
+    fn find_memory_files(
+        dir: &std::path::Path,
+        files: &mut Vec<String>,
+    ) -> std::io::Result<()> {
         if !dir.is_dir() {
             return Ok(());
         }
@@ -1461,16 +1511,25 @@ async fn list_memory_files_native() -> Result<MemoryFilesResponse, String> {
         Ok(())
     }
 
-    if let Err(e) = find_memory_files(&projects_dir, &mut memory_files) {
+    if let Err(e) = find_memory_files(&projects_dir, &mut memory_paths) {
         return Err(format!("Failed to list memory files: {}", e));
     }
 
     // Sort files alphabetically
-    memory_files.sort();
+    memory_paths.sort();
 
-    Ok(MemoryFilesResponse {
-        files: memory_files,
-    })
+    // Read first heading from each file
+    let files = memory_paths
+        .into_iter()
+        .map(|path| {
+            let heading = fs::read_to_string(&path)
+                .ok()
+                .and_then(|content| extract_first_heading(&content));
+            MemoryFileInfo { path, heading }
+        })
+        .collect();
+
+    Ok(MemoryFilesResponse { files })
 }
 
 #[tauri::command]
@@ -2902,4 +2961,65 @@ gitea: gitea-mcp -t stdio (STDIO) - ✓ Connected"#;
         assert_eq!(servers[0].name, "asana");
         assert_eq!(servers[1].name, "gitea");
     }
+
+    // ==================== extract_first_heading tests ====================
+
+    #[test]
+    fn test_extract_first_heading_returns_heading() {
+        let content = "# My Memory File\n\nSome content here.";
+        assert_eq!(
+            extract_first_heading(content),
+            Some("My Memory File".to_string())
+        );
+    }
+
+    #[test]
+    fn test_extract_first_heading_ignores_non_h1() {
+        let content = "## Section Header\n### Sub-section\nSome content.";
+        assert_eq!(extract_first_heading(content), None);
+    }
+
+    #[test]
+    fn test_extract_first_heading_finds_first_h1_after_other_lines() {
+        let content = "Some intro text\n\n# The Real Title\n\nMore content.";
+        assert_eq!(
+            extract_first_heading(content),
+            Some("The Real Title".to_string())
+        );
+    }
+
+    #[test]
+    fn test_extract_first_heading_trims_whitespace() {
+        let content = "#   Trimmed Heading   \n\nContent.";
+        assert_eq!(
+            extract_first_heading(content),
+            Some("Trimmed Heading".to_string())
+        );
+    }
+
+    #[test]
+    fn test_extract_first_heading_returns_none_for_empty_content() {
+        assert_eq!(extract_first_heading(""), None);
+    }
+
+    #[test]
+    fn test_extract_first_heading_returns_none_for_empty_heading() {
+        let content = "# \n\nContent after empty heading.";
+        assert_eq!(extract_first_heading(content), None);
+    }
+
+    #[test]
+    fn test_extract_first_heading_returns_none_when_no_headings() {
+        let content = "Just some plain text.\nNo headings here at all.";
+        assert_eq!(extract_first_heading(content), None);
+    }
+
+    #[test]
+    fn test_extract_first_heading_handles_leading_whitespace_on_line() {
+        let content = "   # Indented Heading\n\nContent.";
+        assert_eq!(
+            extract_first_heading(content),
+            Some("Indented Heading".to_string())
+        );
+    }
 }