Add project-mode tooling: characters, outline, diff and revision status

Rounds out project mode, where the workspace is the project root and one
subfolder holds the manuscript proper:

- Characters and Outline windows, backed by new `characters` and `outline`
  modules that read the cast from character sheets and measure how much of
  the snowflake outline is actually written.
- Edit ▸ Changes… diffs the open file against its last committed version.
- Revision status, per-file and project word counts, an archive action and
  hidden folders in the file panel.
- Chapter-file export alongside the ODT master, richer header parsing, and
  a project word list for names and invented terms.
- The export path now follows the workspace: opening a project points it at
  that project root, keeping a file name you chose yourself and re-deriving
  one that merely echoed the folder it sat in.
- Clicking an issue in the grammar/spelling panel takes the editor to it,
  selecting the words and centring them; applying a suggestion jumps to the
  rewritten text as well.

README covers the new windows and workflows.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017bSn3Xijp8GofZVUnRX4oq

src/config.rs

@@ -11,6 +11,14 @@ pub struct Config {
     /// Whether to show the live preview pane.
     #[serde(default)]
     pub show_preview: bool,
+    /// Whether the editor hides the editorial header, showing the prose alone.
+    #[serde(default)]
+    pub collapse_header: bool,
+    /// Whether the file panel lists a project's reference files (characters,
+    /// outline, scratch pad) alongside the manuscript. Off by default: the panel
+    /// is for the book, and the reference material has windows of its own.
+    #[serde(default)]
+    pub show_reference_files: bool,
     /// Marker line separating a file's editorial header from its prose. Content
     /// above it (except `# Title:` / `# Slug:` metadata) is dropped on export.
     /// An empty value disables header splitting.
@@ -103,6 +111,22 @@ pub struct Config {
     /// like the Mistral key.
     #[serde(default)]
     pub gitea_token: String,
+    /// Folders kept out of the file panel entirely, matched leniently so
+    /// `Archive` covers `10-Archive`. An archive of dead drafts can hold
+    /// hundreds of files that would otherwise swamp the tree.
+    #[serde(default = "default_hidden_folders")]
+    pub hidden_folders: Vec<String>,
+    /// Folder the Archive action moves files into. Matched leniently against
+    /// what the project already has, so `10-Archive` is found and reused.
+    #[serde(default = "default_archive_folder")]
+    pub archive_folder: String,
+    /// Manuscript title written into exported documents. Blank falls back to the
+    /// project folder's name.
+    #[serde(default)]
+    pub manuscript_title: String,
+    /// Author written into exported documents.
+    #[serde(default)]
+    pub manuscript_author: String,
 }
 
 /// Default cookiecutter template for **File ▸ New project…**.
@@ -126,6 +150,17 @@ pub fn default_project_run_hooks() -> bool {
     true
 }
 
+/// Folders excluded from the panel by default: the snowflake layout's archive,
+/// which holds superseded drafts rather than working material.
+pub fn default_hidden_folders() -> Vec<String> {
+    vec!["Archive".to_string()]
+}
+
+/// Default archive folder, matching the snowflake layout.
+pub fn default_archive_folder() -> String {
+    "10-Archive".to_string()
+}
+
 /// Default parent directory for new projects.
 pub fn default_projects_dir() -> PathBuf {
     dirs::document_dir().unwrap_or_else(|| {
@@ -202,6 +237,8 @@ impl Default for Config {
             workspace,
             export_path,
             show_preview: false,
+            collapse_header: false,
+            show_reference_files: false,
             draft_marker: default_marker(),
             zero_pad_index: false,
             editor_zoom: 0.0,
@@ -226,6 +263,10 @@ impl Default for Config {
             gitea_url: String::new(),
             gitea_user: String::new(),
             gitea_token: String::new(),
+            hidden_folders: default_hidden_folders(),
+            archive_folder: default_archive_folder(),
+            manuscript_title: String::new(),
+            manuscript_author: String::new(),
         }
     }
 }