Route CLI format dispatch through shared registry

Cargo.lock

@@ -1675,6 +1675,7 @@ dependencies = [
 name = "designcraft-cli"
 version = "0.20.1"
 dependencies = [
+ "craft-file-formats",
  "designcraft-color",
  "designcraft-compose",
  "designcraft-doc",
@@ -1863,6 +1864,7 @@ dependencies = [
 name = "designcraft-mcp"
 version = "0.20.1"
 dependencies = [
+ "craft-file-formats",
  "designcraft-engine",
  "designcraft-geom",
  "designcraft-render",

apps/designcraft-cli/Cargo.toml

@@ -22,5 +22,6 @@ designcraft-compose = { workspace = true }
 designcraft-format = { workspace = true }
 designcraft-pdf = { workspace = true }
 designcraft-mcp = { workspace = true }
+craft-file-formats = { workspace = true }
 image = { workspace = true }
 serde_json = { workspace = true }

apps/designcraft-cli/src/main.rs

@@ -597,8 +597,8 @@ fn export(s: &mut Session, out: &str, page: usize, scale: f64) -> Result<(), Str
     let img = r
         .render_page(&st.doc, &s.cache, page, scale, true, &designcraft_render::RenderOptions { printing_only: true, ..Default::default() })
         .ok_or("no such page")?;
-    let lower = out.to_lowercase();
-    let bytes = if lower.ends_with(".jpg") || lower.ends_with(".jpeg") { img.to_jpeg(90) } else { img.to_png() };
+    let jpeg = craft_file_formats::detect(out, &[]) == Some(craft_file_formats::Format::Jpeg);
+    let bytes = if jpeg { img.to_jpeg(90) } else { img.to_png() };
     designcraft_engine::atomic::write_atomic(std::path::Path::new(out), &bytes).map_err(|e| format!("{out}: {e}"))?;
     eprintln!("wrote {out} ({}×{}, {:.1} ms, {} glyphs)", img.width, img.height, t.elapsed().as_secs_f64() * 1000.0, r.stats.glyphs);
     Ok(())
@@ -645,7 +645,7 @@ fn script(args: &[String]) -> Result<(), String> {
         match a.as_str() {
             "--in" => {
                 let p = val()?;
-                let cmd = if p.to_lowercase().ends_with(".idml") { "file.openIdml" } else { "file.open" };
+                let cmd = if craft_file_formats::detect(&p, &[]) == Some(craft_file_formats::Format::Idml) { "file.openIdml" } else { "file.open" };
                 setup.push((cmd.into(), json!({"path": p})));
             }
             "--sample" => setup.push(("file.newSample".into(), json!({}))),

crates/engine/src/cmd/book.rs

@@ -130,7 +130,7 @@ impl ChapterBatch {
 fn writable_chapter(s: &Session, path: &str, command: &'static str) -> Result<()> {
     use std::path::Path;
 
-    if Path::new(path).extension().and_then(std::ffi::OsStr::to_str).is_some_and(|ext| ext.eq_ignore_ascii_case("idml")) {
+    if Path::new(path).extension().and_then(std::ffi::OsStr::to_str).is_some_and(|ext| craft_file_formats::from_extension(ext) == Some(craft_file_formats::Format::Idml)) {
         return Err(bad(command, format!("cannot change imported IDML chapter {path}; convert it to a native DesignCraft document first")));
     }
     let target = crate::io::canonicalize(path).map_err(|e| EngineError::Other(format!("{path}: {e}")))?;

crates/mcp/Cargo.toml

@@ -12,6 +12,7 @@ workspace = true
 designcraft-engine = { workspace = true }
 designcraft-render = { workspace = true }
 designcraft-tools = { workspace = true }
+craft-file-formats = { workspace = true }
 designcraft-geom = { workspace = true }
 serde_json = { workspace = true }
 log = { workspace = true }

crates/mcp/src/headless.rs

@@ -259,8 +259,8 @@ impl Headless {
             .renderer
             .render_page(&st.doc, &self.session.cache, page, scale, false, &RenderOptions { printing_only: true, ..Default::default() })
             .ok_or_else(|| format!("no page {page}"))?;
-        let lower = path.to_ascii_lowercase();
-        let bytes = if lower.ends_with(".jpg") || lower.ends_with(".jpeg") { img.to_jpeg(90) } else { img.to_png() };
+        let jpeg = craft_file_formats::detect(path, &[]) == Some(craft_file_formats::Format::Jpeg);
+        let bytes = if jpeg { img.to_jpeg(90) } else { img.to_png() };
         designcraft_engine::io::write_file(path, &bytes)?;
         Ok(json!({"path": path, "width": img.width, "height": img.height}))
     }