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/order.rs

@@ -0,0 +1,84 @@
+use std::collections::HashMap;
+use std::path::Path;
+
+/// Name of the file (inside the workspace) that stores the manual ordering.
+/// It is committed to git so the order syncs across machines.
+pub const ORDER_FILE: &str = "order.json";
+
+/// Name of the file that stores per-file chapter title overrides
+/// (a JSON object mapping `file name` -> `chapter title`). Also committed to git.
+pub const TITLES_FILE: &str = "titles.json";
+
+/// Read the chapter-title overrides. Missing/invalid -> empty map.
+pub fn read_titles(workspace: &Path) -> HashMap<String, String> {
+    let path = workspace.join(TITLES_FILE);
+    match std::fs::read_to_string(&path) {
+        Ok(text) => serde_json::from_str(&text).unwrap_or_default(),
+        Err(_) => HashMap::new(),
+    }
+}
+
+/// Persist the chapter-title overrides as JSON into the workspace.
+pub fn write_titles(workspace: &Path, titles: &HashMap<String, String>) -> std::io::Result<()> {
+    let path = workspace.join(TITLES_FILE);
+    let text = serde_json::to_string_pretty(titles).unwrap_or_else(|_| "{}".to_string());
+    std::fs::write(path, text)
+}
+
+/// Read the saved order (a JSON array of file names). Missing/invalid -> empty.
+fn read_saved_order(workspace: &Path) -> Vec<String> {
+    let path = workspace.join(ORDER_FILE);
+    match std::fs::read_to_string(&path) {
+        Ok(text) => serde_json::from_str(&text).unwrap_or_default(),
+        Err(_) => Vec::new(),
+    }
+}
+
+/// Persist the given order as JSON into the workspace.
+pub fn write_order(workspace: &Path, order: &[String]) -> std::io::Result<()> {
+    let path = workspace.join(ORDER_FILE);
+    let text = serde_json::to_string_pretty(order).unwrap_or_else(|_| "[]".to_string());
+    std::fs::write(path, text)
+}
+
+/// List all `*.md` files currently present in the workspace (file names only).
+fn list_markdown_files(workspace: &Path) -> Vec<String> {
+    let mut files = Vec::new();
+    if let Ok(entries) = std::fs::read_dir(workspace) {
+        for entry in entries.flatten() {
+            let path = entry.path();
+            if path.is_file() {
+                if let Some(ext) = path.extension() {
+                    if ext.eq_ignore_ascii_case("md") {
+                        if let Some(name) = path.file_name().and_then(|n| n.to_str()) {
+                            files.push(name.to_string());
+                        }
+                    }
+                }
+            }
+        }
+    }
+    files
+}
+
+/// Produce the effective ordered list of markdown files:
+///   1. saved-order entries that still exist on disk, in saved order
+///   2. any new `.md` files not yet in the saved order, appended alphabetically
+pub fn resolve_order(workspace: &Path) -> Vec<String> {
+    let saved = read_saved_order(workspace);
+    let mut present = list_markdown_files(workspace);
+    present.sort_by(|a, b| a.to_lowercase().cmp(&b.to_lowercase()));
+
+    let mut result: Vec<String> = Vec::new();
+    for name in &saved {
+        if present.contains(name) && !result.contains(name) {
+            result.push(name.clone());
+        }
+    }
+    for name in present {
+        if !result.contains(&name) {
+            result.push(name);
+        }
+    }
+    result
+}