chore: add EntryFallback completion support

Add `#[completion(EntryFallback)]` syntax to enable custom
completion suggestions for unmatched entries, merging fallback
results with default completions via `Suggest::combine()`.

1 files changed, 3 insertions, 1 deletions

diff --git a/mingling_core/src/comp.rs b/mingling_core/src/comp.rs
index a4e4f0b..021793b 100644
--- a/mingling_core/src/comp.rs
+++ b/mingling_core/src/comp.rs
@@ -163,7 +163,9 @@ impl CompletionHelper {
             }
             None => {
                 trace!("using default completion");
-                default_completion::<P>(ctx)
+                let fallback = P::do_comp(&P::build_entry_fallback(vec![]), ctx);
+                let default = default_completion::<P>(ctx);
+                fallback.combine(default)
             }
         }
     }