fix(aliases): preserve payload rules for surviving channels

Scope payload cleanup to the selected OAuth protocol and retain rules still used by surviving OAuth aliases, API mappings, or real models. Preserve protocol-free shared rules while any matching mapping survives, and limit creation cleanup to its source protocol.

Validation: cargo test --locked tests::alias_delete (6 passed), including Codex/Claude collisions, wildcard selectors, same-protocol OAuth channels, and API mappings.

src-tauri/src/tests/alias_delete.rs

@@ -63,3 +63,65 @@ fn plain_alias_deletion_preserves_real_models_with_the_same_name() {
     );
     assert!(remove_thinking_alias_from_yaml(&deleted, "plain").is_err());
 }
+
+#[test]
+fn channel_deletion_preserves_other_protocols_and_shared_models() {
+    let original = "oauth-model-alias:\n  codex: [{name: model-a, alias: shared}]\n  claude: [{name: model-b, alias: shared}]\npayload:\n  override:\n    - models: [{name: shared, protocol: codex}]\n      params: {reasoning.effort: high, service_tier: priority}\n    - models: [{name: shared, protocol: claude}, {name: other, protocol: codex}]\n      params: {output_config.effort: high}\n";
+    for speed in [false, true] {
+        let deleted = if speed {
+            remove_speed_alias_from_yaml_for_channel(original, "shared", Some("codex"))
+        } else {
+            remove_thinking_alias_from_yaml_for_channel(original, "shared", Some("codex"))
+        }
+        .unwrap();
+        let entries = thinking_aliases_from_yaml(&deleted).unwrap();
+        assert_eq!(entries.len(), 1);
+        assert_eq!(entries[0].oauth_channel.as_deref(), Some("claude"));
+        assert_eq!(entries[0].effort.as_deref(), Some("high"));
+        assert_eq!(
+            json(&deleted)["payload"]["override"],
+            serde_json::json!([json(original)["payload"]["override"][1]])
+        );
+    }
+}
+
+#[test]
+fn channel_deletion_preserves_wildcard_rules_for_surviving_aliases() {
+    for protocol in ["", ", protocol: ''"] {
+        let original = format!("oauth-model-alias:\n  codex: [{{name: model-a, alias: shared}}]\n  claude: [{{name: model-b, alias: shared}}]\npayload:\n  override:\n    - models: [{{name: shared{protocol}}}]\n      params: {{reasoning.effort: high, output_config.effort: high, service_tier: priority}}\n");
+        for speed in [false, true] {
+            let deleted = if speed {
+                remove_speed_alias_from_yaml_for_channel(&original, "shared", Some("codex"))
+            } else {
+                remove_thinking_alias_from_yaml_for_channel(&original, "shared", Some("codex"))
+            }
+            .unwrap();
+            assert_eq!(json(&deleted)["payload"], json(&original)["payload"]);
+            let deleted =
+                remove_thinking_alias_from_yaml_for_channel(&deleted, "shared", Some("claude"))
+                    .unwrap();
+            assert!(json(&deleted).get("payload").is_none());
+        }
+    }
+}
+
+#[test]
+fn channel_deletion_preserves_rules_used_by_same_protocol_mappings() {
+    for surviving in [
+        "  xai: [{name: model-b, alias: shared}]\n",
+        "codex-api-key:\n  - models: [{name: model-b, alias: shared}]\n",
+        "codex-api-key:\n  - models: [{name: shared}]\n",
+    ] {
+        let original = format!("oauth-model-alias:\n  codex: [{{name: model-a, alias: shared}}]\n{surviving}payload:\n  override:\n    - models: [{{name: shared, protocol: codex}}]\n      params: {{reasoning.effort: high, service_tier: priority}}\n");
+        for speed in [false, true] {
+            let deleted = if speed {
+                remove_speed_alias_from_yaml_for_channel(&original, "shared", Some("codex"))
+            } else {
+                remove_thinking_alias_from_yaml_for_channel(&original, "shared", Some("codex"))
+            }
+            .unwrap();
+            assert_eq!(json(&deleted)["payload"], json(&original)["payload"]);
+            assert!(json(&deleted)["oauth-model-alias"].get("codex").is_none());
+        }
+    }
+}