Initial commit: md-manuscript editor

Rust/egui desktop app: draggable markdown file list, editor, git sync,
per-file chapter titles, and native ODT export. Includes README and
Debian 12 (Surface) install guide.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/config.rs

@@ -0,0 +1,61 @@
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+/// Persistent application configuration (which workspace to open, plus UI prefs).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Config {
+    /// Directory that holds the markdown files and the git repository.
+    pub workspace: PathBuf,
+    /// Last used ODT export path.
+    pub export_path: PathBuf,
+    /// Whether to show the live preview pane.
+    #[serde(default)]
+    pub show_preview: bool,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        let workspace = default_workspace();
+        let export_path = workspace.join("manuscript.odt");
+        Config {
+            workspace,
+            export_path,
+            show_preview: false,
+        }
+    }
+}
+
+/// The dedicated directory where manuscripts live by default: ~/Manuscript.
+pub fn default_workspace() -> PathBuf {
+    dirs::home_dir()
+        .unwrap_or_else(|| PathBuf::from("."))
+        .join("Manuscript")
+}
+
+/// Location of the config file: ~/.config/md-manuscript/config.json
+fn config_path() -> PathBuf {
+    dirs::config_dir()
+        .unwrap_or_else(|| PathBuf::from("."))
+        .join("md-manuscript")
+        .join("config.json")
+}
+
+impl Config {
+    pub fn load() -> Config {
+        let path = config_path();
+        match std::fs::read_to_string(&path) {
+            Ok(text) => serde_json::from_str(&text).unwrap_or_default(),
+            Err(_) => Config::default(),
+        }
+    }
+
+    pub fn save(&self) {
+        let path = config_path();
+        if let Some(parent) = path.parent() {
+            let _ = std::fs::create_dir_all(parent);
+        }
+        if let Ok(text) = serde_json::to_string_pretty(self) {
+            let _ = std::fs::write(&path, text);
+        }
+    }
+}