fix: vault cache misses files in new directories, breaking theme restore

Root cause: git_uncommitted_files() used `git status --porcelain` which
reports new untracked directories as `?? theme/` instead of listing
individual files inside. The .md filter skipped directory entries, so
files in newly-created directories (theme/default.md, etc.) were
invisible to the cache system.

Fix: additionally use `git ls-files --others --exclude-standard` which
lists individual untracked files, resolving directories to their
contents.

Also:
- Add type/theme.md definition (icon: palette) to restore and getting-started vault
- Seed theme/*.md vault notes in getting-started vault
- Fix mock create_vault_theme to add entries for dev mode

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src-tauri/src/theme/defaults.rs

@@ -329,3 +329,15 @@ editor-max-width: 680\n\
 # Minimal Theme\n\
 \n\
 High contrast, minimal chrome. Monospace typography throughout.\n";
+
+/// Type definition for the Theme note type.
+pub const THEME_TYPE_DEFINITION: &str = "---\n\
+Is A: Type\n\
+icon: palette\n\
+color: purple\n\
+order: 50\n\
+---\n\
+\n\
+# Theme\n\
+\n\
+A visual theme for Laputa. Each theme defines CSS custom properties that control colors, typography, and spacing.\n";

src-tauri/src/theme/mod.rs

@@ -10,7 +10,8 @@ use std::path::Path;
 pub use create::{create_theme, create_vault_theme};
 pub use defaults::*;
 pub use seed::{
-    ensure_vault_themes, restore_default_themes, seed_default_themes, seed_vault_themes,
+    ensure_theme_type_definition, ensure_vault_themes, restore_default_themes,
+    seed_default_themes, seed_vault_themes,
 };
 
 /// A theme file parsed from _themes/*.json in the vault.

src-tauri/src/theme/seed.rs

@@ -104,9 +104,26 @@ pub fn restore_default_themes(vault_path: &str) -> Result<String, String> {
     // Seed theme/ markdown notes (reuses ensure_vault_themes for consistency)
     ensure_vault_themes(vault_path)?;
 
+    // Seed type/theme.md so the Theme type has an icon and label in the sidebar
+    ensure_theme_type_definition(vault_path)?;
+
     Ok("Default themes restored".to_string())
 }
 
+/// Create `type/theme.md` if it doesn't exist (gives the Theme type a sidebar icon/color).
+pub fn ensure_theme_type_definition(vault_path: &str) -> Result<(), String> {
+    let type_dir = Path::new(vault_path).join("type");
+    fs::create_dir_all(&type_dir)
+        .map_err(|e| format!("Failed to create type directory: {e}"))?;
+    let path = type_dir.join("theme.md");
+    let needs_write = !path.exists() || fs::metadata(&path).map_or(true, |m| m.len() == 0);
+    if needs_write {
+        fs::write(&path, THEME_TYPE_DEFINITION)
+            .map_err(|e| format!("Failed to write type/theme.md: {e}"))?;
+    }
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -244,6 +261,46 @@ mod tests {
         assert!(vault.join("theme").join("default.md").exists());
         assert!(vault.join("theme").join("dark.md").exists());
         assert!(vault.join("theme").join("minimal.md").exists());
+        assert!(
+            vault.join("type").join("theme.md").exists(),
+            "restore must create type/theme.md"
+        );
+        let type_content = fs::read_to_string(vault.join("type").join("theme.md")).unwrap();
+        assert!(type_content.contains("Is A: Type"));
+        assert!(type_content.contains("icon: palette"));
+    }
+
+    #[test]
+    fn test_ensure_theme_type_definition_creates_file() {
+        let dir = TempDir::new().unwrap();
+        let vault = dir.path().join("vault");
+        fs::create_dir_all(&vault).unwrap();
+        let vp = vault.to_str().unwrap();
+
+        ensure_theme_type_definition(vp).unwrap();
+        let path = vault.join("type").join("theme.md");
+        assert!(path.exists());
+        let content = fs::read_to_string(&path).unwrap();
+        assert!(content.contains("Is A: Type"));
+        assert!(content.contains("icon: palette"));
+    }
+
+    #[test]
+    fn test_ensure_theme_type_definition_is_idempotent() {
+        let dir = TempDir::new().unwrap();
+        let vault = dir.path().join("vault");
+        let type_dir = vault.join("type");
+        fs::create_dir_all(&type_dir).unwrap();
+        let custom = "---\nIs A: Type\nicon: swatches\ncolor: green\n---\n# Theme\n";
+        fs::write(type_dir.join("theme.md"), custom).unwrap();
+        let vp = vault.to_str().unwrap();
+
+        ensure_theme_type_definition(vp).unwrap();
+        let content = fs::read_to_string(type_dir.join("theme.md")).unwrap();
+        assert!(
+            content.contains("swatches"),
+            "existing content must be preserved"
+        );
     }
 
     #[test]