feat(cron): add --session-key option to cron add/edit CLI commands

Expose the existing CronJob.sessionKey field through the CLI so users
can target cron jobs at specific named sessions without needing an
external shell script + system crontab workaround.

The backend already fully supports sessionKey on cron jobs - this
change wires it to the CLI surface with --session-key on cron add,
and --session-key / --clear-session-key on cron edit.

Closes #27158

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/cli/cron-cli/register.cron-edit.ts

@@ -37,6 +37,8 @@ export function registerCronEditCommand(cron: Command) {
       .option("--session <target>", "Session target (main|isolated)")
       .option("--agent <id>", "Set agent id")
       .option("--clear-agent", "Unset agent and use default", false)
+      .option("--session-key <key>", "Set session key for job routing")
+      .option("--clear-session-key", "Unset session key", false)
       .option("--wake <mode>", "Wake mode (now|next-heartbeat)")
       .option("--at <when>", "Set one-shot time (ISO) or duration like 20m")
       .option("--every <duration>", "Set interval duration like 10m")
@@ -133,6 +135,15 @@ export function registerCronEditCommand(cron: Command) {
           if (opts.clearAgent) {
             patch.agentId = null;
           }
+          if (opts.sessionKey && opts.clearSessionKey) {
+            throw new Error("Use --session-key or --clear-session-key, not both");
+          }
+          if (typeof opts.sessionKey === "string" && opts.sessionKey.trim()) {
+            patch.sessionKey = opts.sessionKey.trim();
+          }
+          if (opts.clearSessionKey) {
+            patch.sessionKey = null;
+          }
 
           const scheduleChosen = [opts.at, opts.every, opts.cron].filter(Boolean).length;
           if (scheduleChosen > 1) {