Remove stray .snap.new filtering from schema fixtures reader

Motivation:
- `codex-app-server-protocol` schema fixtures are not insta snapshots.
- Filtering `*.snap.new` is confusing and risks hiding real files.

What changed:
- Remove the `.snap.new` filename special case in `read_schema_fixture_tree`.

Refs: macOS Bazel schema fixture mismatch investigation

codex-rs/app-server-protocol/schema/json/CommandExecutionRequestApprovalResponse.json

@@ -0,0 +1,72 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "CommandExecutionApprovalDecision": {
+      "oneOf": [
+        {
+          "description": "User approved the command.",
+          "enum": [
+            "accept"
+          ],
+          "type": "string"
+        },
+        {
+          "description": "User approved the command and future identical commands should run without prompting.",
+          "enum": [
+            "acceptForSession"
+          ],
+          "type": "string"
+        },
+        {
+          "additionalProperties": false,
+          "description": "User approved the command, and wants to apply the proposed execpolicy amendment so future matching commands can run without prompting.",
+          "properties": {
+            "acceptWithExecpolicyAmendment": {
+              "properties": {
+                "execpolicy_amendment": {
+                  "items": {
+                    "type": "string"
+                  },
+                  "type": "array"
+                }
+              },
+              "required": [
+                "execpolicy_amendment"
+              ],
+              "type": "object"
+            }
+          },
+          "required": [
+            "acceptWithExecpolicyAmendment"
+          ],
+          "title": "AcceptWithExecpolicyAmendmentCommandExecutionApprovalDecision",
+          "type": "object"
+        },
+        {
+          "description": "User denied the command. The agent will continue the turn.",
+          "enum": [
+            "decline"
+          ],
+          "type": "string"
+        },
+        {
+          "description": "User denied the command. The turn will also be immediately interrupted.",
+          "enum": [
+            "cancel"
+          ],
+          "type": "string"
+        }
+      ]
+    }
+  },
+  "properties": {
+    "decision": {
+      "$ref": "#/definitions/CommandExecutionApprovalDecision"
+    }
+  },
+  "required": [
+    "decision"
+  ],
+  "title": "CommandExecutionRequestApprovalResponse",
+  "type": "object"
+}