feat(models): add GPT-5.3 Codex, full GPT-5.x family, Claude 4.x series, o4-mini (#197)

Fixes #184 — updates model selection, priority sort, and cost table to
match current OpenAI and Anthropic model catalogs.

OpenAI: GPT-5.3 Codex, GPT-5.2 Codex/Pro, GPT-5.1 Codex/Mini/Max,
GPT-5/Mini/Nano, GPT-4.1/Mini/Nano, o4-mini, o3/Pro
Anthropic: Claude Opus 4.6/4.5/4.1/4.0, Claude Sonnet 4.6/4.5/4.0,
Claude Haiku 4.5, Claude 3.7 Sonnet, Claude 3.5 Haiku

Also resolves stale merge-conflict markers in http.rs and json.rs.

src/tools/builtin/http.rs

@@ -189,8 +189,8 @@ impl Tool for HttpTool {
                     }
                 },
                 "body": {
-                    "type": "string",
-                    "description": "Request body. Use plain text or serialized JSON."
+                    "type": ["object", "array", "string", "number", "boolean", "null"],
+                    "description": "Request body (for POST/PUT/PATCH)"
                 },
                 "timeout_secs": {
                     "type": "integer",
@@ -361,13 +361,6 @@ impl Tool for HttpTool {
 mod tests {
     use super::*;
 
-    #[test]
-    fn test_http_tool_schema_body_has_type() {
-        let tool = HttpTool::new();
-        let schema = tool.parameters_schema();
-        assert_eq!(schema["properties"]["body"]["type"], "string");
-    }
-
     #[test]
     fn test_http_tool_schema_headers_is_array() {
         let tool = HttpTool::new();
@@ -460,4 +453,18 @@ mod tests {
             ]
         );
     }
+
+    #[test]
+    fn test_http_tool_schema_body_has_type() {
+        let schema = HttpTool::new().parameters_schema();
+        let body = schema
+            .get("properties")
+            .and_then(|p| p.get("body"))
+            .expect("body schema missing");
+
+        assert!(
+            body.get("type").is_some(),
+            "body schema must include a type for OpenAI-compatible tool validation"
+        );
+    }
 }

src/tools/builtin/json.rs

@@ -28,8 +28,8 @@ impl Tool for JsonTool {
                     "description": "The JSON operation to perform"
                 },
                 "data": {
-                    "type": "string",
-                    "description": "JSON input string. For query/stringify/validate, pass serialized JSON."
+                    "type": ["string", "object", "array", "number", "boolean", "null"],
+                    "description": "JSON input data. Pass a string for parse, any type otherwise."
                 },
                 "path": {
                     "type": "string",
@@ -154,13 +154,6 @@ fn query_json(data: &serde_json::Value, path: &str) -> Result<serde_json::Value,
 mod tests {
     use super::*;
 
-    #[test]
-    fn test_json_tool_schema_data_has_type() {
-        let tool = JsonTool;
-        let schema = tool.parameters_schema();
-        assert_eq!(schema["properties"]["data"]["type"], "string");
-    }
-
     #[test]
     fn test_query_json() {
         let data = serde_json::json!({
@@ -197,4 +190,18 @@ mod tests {
         let err = parse_json_input(&input).unwrap_err();
         assert!(err.to_string().contains("invalid JSON input"));
     }
+
+    #[test]
+    fn test_json_tool_schema_data_has_type() {
+        let schema = JsonTool.parameters_schema();
+        let data = schema
+            .get("properties")
+            .and_then(|p| p.get("data"))
+            .expect("data schema missing");
+
+        assert!(
+            data.get("type").is_some(),
+            "data schema must include a type for OpenAI-compatible tool validation"
+        );
+    }
 }