feat(cli): add harper chat alias for harper agent

Per PR #1553 discussion — makes clear this is a lightweight chat client
for the built-in agent, not a harper-agent replacement.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: kriszyp

bin/agentCli.ts

@@ -39,7 +39,7 @@ interface Connection {
 	label: string;
 }
 
-const HELP = `harper agent — interact with the built-in Harper agent
+const HELP = `harper agent — interact with the built-in Harper agent (alias: harper chat)
 
 Usage:
   harper agent [message]              Send a prompt (one-shot) and print the reply

bin/harper.ts

@@ -23,7 +23,7 @@ Documentation: https://docs.harperdb.io/
 By default, the CLI also supports certain Operation APIs. Specify the operation name and any required parameters, and omit the 'operation' command.
 
 Commands:
-agent [message]                 - Chat with the built-in agent (interactive, or one-shot with a message)
+agent [message]                 - Chat with the built-in agent (interactive, or one-shot with a message; alias: chat)
 copy-db <source> <target>       - Copies a database from source path to target path
 dev <path>                      - Run the application in dev mode with debugging, foreground logging, no auth
 install                         - Install harperdb
@@ -112,6 +112,7 @@ async function harper() {
 			const code = await runMcpCli(process.argv.slice(3));
 			process.exit(code);
 		}
+		case SERVICE_ACTIONS_ENUM.CHAT:
 		case SERVICE_ACTIONS_ENUM.AGENT: {
 			const { runAgentCli } = require('./agentCli');
 			const code = await runAgentCli(process.argv.slice(3));

utility/hdbTerms.ts

@@ -394,6 +394,7 @@ export const SERVICE_ACTIONS_ENUM = {
 	COPYDB: 'copy-db',
 	MCP: 'mcp',
 	AGENT: 'agent',
+	CHAT: 'chat',
 } as const;
 
 /** describes the Geo Conversion types */