feat: add memory system activity display

Implements issue #118 to display auto-memory system operations and
provide a browser for viewing memory files.

Backend changes:
- Detect memory file operations in format_tool_description()
- Add emoji icons (📝/💾) for memory Read/Write/Edit operations
- Add list_memory_files() Tauri command to find all memory files
- Add 4 new tests for memory detection logic
- Update Tauri capabilities to allow reading .claude directory

Frontend changes:
- Create MemoryBrowserPanel component with file list and viewer
- Add memory panel to main app layout
- Support Markdown rendering of memory file contents
- Add loading states and error handling

Testing:
- All 354 Rust tests passing
- TypeScript type-checks pass

Co-Authored-By: Hikari <hikari@nhcarrigan.com>

src-tauri/src/commands.rs

@@ -1167,6 +1167,76 @@ pub async fn close_application(app_handle: AppHandle) -> Result<(), String> {
     Ok(())
 }
 
+#[derive(serde::Serialize)]
+pub struct MemoryFilesResponse {
+    pub files: Vec<String>,
+}
+
+#[tauri::command]
+pub async fn list_memory_files() -> Result<MemoryFilesResponse, String> {
+    use std::fs;
+
+    // Get the .claude directory in the user's home
+    let home_dir = match dirs::home_dir() {
+        Some(dir) => dir,
+        None => return Err("Could not find home directory".to_string()),
+    };
+
+    let claude_dir = home_dir.join(".claude");
+    let projects_dir = claude_dir.join("projects");
+
+    if !projects_dir.exists() {
+        return Ok(MemoryFilesResponse { files: Vec::new() });
+    }
+
+    let mut memory_files = Vec::new();
+
+    // Recursively find all memory directories
+    fn find_memory_files(dir: &std::path::Path, files: &mut Vec<String>) -> std::io::Result<()> {
+        if !dir.is_dir() {
+            return Ok(());
+        }
+
+        for entry in fs::read_dir(dir)? {
+            let entry = entry?;
+            let path = entry.path();
+
+            if path.is_dir() {
+                // Check if this is a "memory" directory
+                if path.file_name().and_then(|n| n.to_str()) == Some("memory") {
+                    // List all files in the memory directory
+                    for mem_entry in fs::read_dir(&path)? {
+                        let mem_entry = mem_entry?;
+                        let mem_path = mem_entry.path();
+
+                        if mem_path.is_file() {
+                            if let Some(path_str) = mem_path.to_str() {
+                                files.push(path_str.to_string());
+                            }
+                        }
+                    }
+                } else {
+                    // Recurse into subdirectories
+                    find_memory_files(&path, files)?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    if let Err(e) = find_memory_files(&projects_dir, &mut memory_files) {
+        return Err(format!("Failed to list memory files: {}", e));
+    }
+
+    // Sort files alphabetically
+    memory_files.sort();
+
+    Ok(MemoryFilesResponse {
+        files: memory_files,
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;