Error::Fennel now wraps FennelError via #[from], preserving miette
source labels and line information. Removes four .map_err closures.

Assisted-by: GLM-5.1 via pi

diff --git a/src/error.rs b/src/error.rs
index 7f4940c..c930e2f 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -12,8 +12,8 @@ pub enum Error {
     #[error("config not found: {0}")]
     ConfigNotFound(String),
 
-    #[error("fennel error: {0}")]
-    Fennel(String),
+    #[error(transparent)]
+    Fennel(#[from] crate::fennel::FennelError),
 
     #[error("git error: {0}")]
     Git(String),
diff --git a/src/quire.rs b/src/quire.rs
index 6eee5c9..3935aaf 100644
--- a/src/quire.rs
+++ b/src/quire.rs
@@ -91,10 +91,8 @@ impl Repo {
             ))
         })?;
 
-        let fennel = Fennel::new().map_err(|e| crate::Error::Fennel(e.to_string()))?;
-        fennel
-            .load_string(&source, "HEAD:.quire/config.fnl")
-            .map_err(|e| crate::Error::Fennel(e.to_string()))
+        let fennel = Fennel::new()?;
+        Ok(fennel.load_string(&source, "HEAD:.quire/config.fnl")?)
     }
 }
 
@@ -141,10 +139,8 @@ impl Quire {
                 config_path.display().to_string(),
             ));
         }
-        let fennel = Fennel::new().map_err(|e| crate::Error::Fennel(e.to_string()))?;
-        fennel
-            .load_file(&config_path)
-            .map_err(|e| crate::Error::Fennel(e.to_string()))
+        let fennel = Fennel::new()?;
+        Ok(fennel.load_file(&config_path)?)
     }
 
     /// Validate a repository name and return its resolved path.