[editor] Only Persist Changed Model Settings (#551)

# Only Persist Changed Model Settings

Fix a bug in the settings renderer copied from workbooks -- currently,
just opening the settings tab and saving the workbook will persist a
model settings object for the prompt. The cause of this is the use of
the `useEffect` for handling changes -- `useEffect` will always run once
on mount of the component so it was always persisting the empty settings
on mount.

To fix, just check that the value has actually changed before persisting
it to the config.

## Testing:
- Open settings & save config without touching anything. See the config
has no changes
- Change system prompt and save, ensure it's persisted to the config
---
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[ReviewStack](https://reviewstack.dev/lastmile-ai/aiconfig/pull/551).
* #552
* __->__ #551

cli/aiconfig-editor/src/components/SettingsPropertyRenderer.tsx

@@ -16,6 +16,7 @@ import {
 import { useState, useCallback, useEffect, useMemo, memo, useRef } from "react";
 import { uniqueId } from "lodash";
 import { IconHelp, IconPlus, IconTrash } from "@tabler/icons-react";
+import { usePrevious } from "@mantine/hooks";
 
 type Props = {
   propertyName: string;
@@ -61,7 +62,11 @@ export default function SettingsPropertyRenderer({
 
   let propertyControl;
 
+  const prevValue = usePrevious(propertyValue);
   useEffect(() => {
+    if (prevValue === propertyValue) {
+      return;
+    }
     if (propertyName != null && propertyName.trim() !== "") {
       setValue((oldValue: any) => {
         return {
@@ -72,7 +77,7 @@ export default function SettingsPropertyRenderer({
     } else {
       setValue(propertyValue);
     }
-  }, [propertyName, propertyValue, setValue]);
+  }, [prevValue, propertyName, propertyValue, setValue]);
 
   // Used in the case the property is an array
   // TODO: Should initialize with values from settings if available

cli/aiconfig-editor/src/shared/prompt_schemas/OpenAIChatModelParserPromptSchema.ts

@@ -66,7 +66,6 @@ export const OpenAIChatModelParserPromptSchema: PromptSchema = {
         type: "integer",
         maximum: 4096,
         minimum: 16,
-        default: 4096,
       },
       n: {
         type: "integer",