feat: add /config chat config updates

src/config/config-paths.ts

@@ -0,0 +1,88 @@
+type PathNode = Record<string, unknown>;
+
+const BLOCKED_KEYS = new Set(["__proto__", "prototype", "constructor"]);
+
+export function parseConfigPath(raw: string): {
+  ok: boolean;
+  path?: string[];
+  error?: string;
+} {
+  const trimmed = raw.trim();
+  if (!trimmed) {
+    return { ok: false, error: "Invalid path. Use dot notation (e.g. foo.bar)." };
+  }
+  const parts = trimmed.split(".").map((part) => part.trim());
+  if (parts.some((part) => !part)) {
+    return { ok: false, error: "Invalid path. Use dot notation (e.g. foo.bar)." };
+  }
+  if (parts.some((part) => BLOCKED_KEYS.has(part))) {
+    return { ok: false, error: "Invalid path segment." };
+  }
+  return { ok: true, path: parts };
+}
+
+export function setConfigValueAtPath(
+  root: PathNode,
+  path: string[],
+  value: unknown,
+): void {
+  let cursor: PathNode = root;
+  for (let idx = 0; idx < path.length - 1; idx += 1) {
+    const key = path[idx];
+    const next = cursor[key];
+    if (!isPlainObject(next)) {
+      cursor[key] = {};
+    }
+    cursor = cursor[key] as PathNode;
+  }
+  cursor[path[path.length - 1]] = value;
+}
+
+export function unsetConfigValueAtPath(
+  root: PathNode,
+  path: string[],
+): boolean {
+  const stack: Array<{ node: PathNode; key: string }> = [];
+  let cursor: PathNode = root;
+  for (let idx = 0; idx < path.length - 1; idx += 1) {
+    const key = path[idx];
+    const next = cursor[key];
+    if (!isPlainObject(next)) return false;
+    stack.push({ node: cursor, key });
+    cursor = next;
+  }
+  const leafKey = path[path.length - 1];
+  if (!(leafKey in cursor)) return false;
+  delete cursor[leafKey];
+  for (let idx = stack.length - 1; idx >= 0; idx -= 1) {
+    const { node, key } = stack[idx];
+    const child = node[key];
+    if (isPlainObject(child) && Object.keys(child).length === 0) {
+      delete node[key];
+    } else {
+      break;
+    }
+  }
+  return true;
+}
+
+export function getConfigValueAtPath(
+  root: PathNode,
+  path: string[],
+): unknown {
+  let cursor: unknown = root;
+  for (const key of path) {
+    if (!isPlainObject(cursor)) return undefined;
+    cursor = cursor[key];
+  }
+  return cursor;
+}
+
+function isPlainObject(value: unknown): value is Record<string, unknown> {
+  return (
+    typeof value === "object" &&
+    value !== null &&
+    !Array.isArray(value) &&
+    Object.prototype.toString.call(value) === "[object Object]"
+  );
+}