feat(cli): add --name flag to update node command

Fixes issue #17: Users can now update the name field of existing nodes
via \`sysprom update node <id> --name "New name"\`.

Previously, only --status and --lifecycle could be updated; text fields
like name, description, context, and rationale were documented as
updatable but not actually exposed in the CLI.

This change makes the update command consistent with the add command,
allowing all text fields (name, description, context, rationale) to be
modified after node creation.

Closes #17

Author: Mearman

src/cli/commands/update.ts

@@ -63,6 +63,7 @@ const updateNodeArgs = z.object({
 	id: z.string().describe("node ID to update"),
 });
 const updateNodeOpts = mutationOpts.extend({
+	name: z.string().optional().describe("update node name"),
 	description: z.string().optional().describe("update node description"),
 	status: NodeStatus.optional().describe("set lifecycle state to true"),
 	context: z.string().optional().describe("update node context"),
@@ -118,6 +119,7 @@ const nodeSubcommand: CommandDef = {
 
 		const fields: Record<string, unknown> = {};
 
+		if (opts.name !== undefined) fields.name = opts.name;
 		if (opts.description !== undefined) fields.description = opts.description;
 		if (opts.context !== undefined) fields.context = opts.context;
 		if (opts.rationale !== undefined) fields.rationale = opts.rationale;
@@ -135,7 +137,7 @@ const nodeSubcommand: CommandDef = {
 		if (Object.keys(fields).length === 0) {
 			console.error("No fields specified to update.");
 			console.error(
-				"Use --description, --status, --context, --rationale, --selected, or --lifecycle.",
+				"Use --name, --description, --status, --context, --rationale, --selected, or --lifecycle.",
 			);
 			process.exit(1);
 		}