[ty] Prefer unqualified imports over qualified imports

It seems like this is perhaps a better default:
https://github.com/astral-sh/ty/issues/1274#issuecomment-3352233790

For me personally, I think I'd prefer the qualified
variant. But I can easily see this changing based on
the specific scenario. I think the thing that pushes
me toward prioritizing the unqualified variant is that
the user could have typed the qualified variant themselves,
but they didn't. So we should perhaps prioritize the
form they typed, which is unqualified.

crates/ty_ide/src/completion.rs

@@ -6625,8 +6625,8 @@ TypedDi<CURSOR>
         assert_snapshot!(
             builder.imports().build().snapshot(),
             @r"
-        typing.TypedDict :: <no import edit>
-        typing.is_typeddict :: <no import edit>
+        TypedDict :: , TypedDict
+        is_typeddict :: , is_typeddict
         _FilterConfigurationTypedDict :: from logging.config import _FilterConfigurationTypedDict
 
         _FormatterConfigurationTypedDict :: from logging.config import _FormatterConfigurationTypedDict

crates/ty_ide/src/importer.rs

@@ -745,8 +745,17 @@ impl ImportResponseKind<'_> {
     fn priority(&self) -> usize {
         match *self {
             ImportResponseKind::Unqualified { .. } => 0,
-            ImportResponseKind::Qualified { .. } => 1,
-            ImportResponseKind::Partial(_) => 2,
+            ImportResponseKind::Partial(_) => 1,
+            // N.B. When given the choice between adding a
+            // name to an existing `from ... import ...`
+            // statement and using an existing `import ...`
+            // in a qualified manner, we currently choose
+            // the former. Originally we preferred qualification,
+            // but there is some evidence that this violates
+            // expectations.
+            //
+            // Ref: https://github.com/astral-sh/ty/issues/1274#issuecomment-3352233790
+            ImportResponseKind::Qualified { .. } => 2,
         }
     }
 }
@@ -1332,9 +1341,9 @@ import collections
         );
         assert_snapshot!(
             test.import("collections", "defaultdict"), @r"
-        from collections import OrderedDict
+        from collections import OrderedDict, defaultdict
         import collections
-        collections.defaultdict
+        defaultdict
         ");
     }