feat(menu): allow overwriting links

Previously when a link was put into menu it was impossible to overwrite
it without editing the database. Instead, we can change our INSERT to
an UPSERT to allow that. This lets me fix typos (such as y/bsky missing
the /profile/ path)

menu/.sqlx/query-735cda2fe387b6b852a03ba7ccba41353667bd505f80c1cfe3ad16b738b45ba5.json

···
-{
-  "db_name": "PostgreSQL",
-  "query": "INSERT INTO direct (\"from\", \"to\", \"owner\") VALUES ($1, $2, $3)",
-  "describe": {
-    "columns": [],
-    "parameters": {
-      "Left": [
-        "Varchar",
-        "Varchar",
-        "Varchar"
-      ]
-    },
-    "nullable": []
-  },
-  "hash": "735cda2fe387b6b852a03ba7ccba41353667bd505f80c1cfe3ad16b738b45ba5"
-}

menu/.sqlx/query-9eecf9b43e5458bc95fc45fe8e48d6da5edb50cdbf1e7a478faf310d6b9022ad.json

···
+{
+  "db_name": "PostgreSQL",
+  "query": "INSERT INTO direct (\"from\", \"to\", \"owner\") VALUES ($1, $2, $3) ON CONFLICT (\"from\") DO UPDATE SET \"to\" = EXCLUDED.to, \"owner\" = EXCLUDED.owner",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Varchar",
+        "Varchar",
+        "Varchar"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "9eecf9b43e5458bc95fc45fe8e48d6da5edb50cdbf1e7a478faf310d6b9022ad"
+}

menu/.sqlx/query-9eecf9b43e5458bc95fc45fe8e48d6da5edb50cdbf1e7a478faf310d6b9022ad.json.license

···
+SPDX-FileCopyrightText: 2026 Freshly Baked Cake
+
+SPDX-License-Identifier: CC0-1.0

menu/src/main.rs

···
     };
 
     let create_call = sqlx::query!(
-        r#"INSERT INTO direct ("from", "to", "owner") VALUES ($1, $2, $3)"#,
+        r#"INSERT INTO direct ("from", "to", "owner") VALUES ($1, $2, $3) ON CONFLICT ("from") DO UPDATE SET "to" = EXCLUDED.to, "owner" = EXCLUDED.owner"#,
         create.from.to_lowercase(),
         create.to,
         owner,