Fix schema inconsistencies in rooms.ts

Description:

In packages/rest-typings/src/v1/rooms.ts, two inconsistencies exist between the TypeScript types and their corresponding AJV schemas in RoomsCreateDiscussionSchema and membersOrderedByRoleRolePropsSchema.

Expected Behavior

• RoomsCreateDiscussionSchema should include the topic field to match the RoomsCreateDiscussionProps TypeScript type so clients sending topic have it correctly passed through.
• membersOrderedByRoleRolePropsSchema should have type: 'object' at the root level, consistent with all other schemas in the file, so AJV correctly rejects non-object inputs.

Current Behavior

// topic declared in type but missing from schema
type RoomsCreateDiscussionProps = {
	...
	topic?: string; // exists in type
};

const RoomsCreateDiscussionSchema = {
	type: 'object',
	properties: {
		...
		reply: { type: 'string', nullable: true },
		// topic missing here — silently stripped by additionalProperties: false
	},
	required: ['prid', 't_name'],
	additionalProperties: false,
};

// missing type: 'object' at root
const membersOrderedByRoleRolePropsSchema = {
	// missing type: 'object'
	properties: { ... },
	oneOf: [{ required: ['roomId'] }, { required: ['roomName'] }],
	additionalProperties: false,
};

Steps to Reproduce

See packages/rest-typings/src/v1/rooms.ts

Additional Context

• Every other schema in the file has type: 'object' at the root making the omission a clear inconsistency
• additionalProperties: false actively strips topic from every request silently with no error
• Both fixes are purely additive with no runtime behavior changes for any valid existing client

Open packages/rest-typings/src/v1/rooms.ts and compare RoomsCreateDiscussionProps with RoomsCreateDiscussionSchema, then inspect membersOrderedByRoleRolePropsSchema against the other schemas in the file. Add the missing schema definitions and verify that topic is accepted and non-object inputs are rejected as described.