feat(update): add core auto-updater and dry-run preview

src/cli/update-cli.ts

@@ -37,6 +37,7 @@ export function registerUpdateCli(program: Command) {
     .description("Update OpenClaw and inspect update channel status")
     .option("--json", "Output result as JSON", false)
     .option("--no-restart", "Skip restarting the gateway service after a successful update")
+    .option("--dry-run", "Preview update actions without making changes", false)
     .option("--channel <stable|beta|dev>", "Persist update channel (git + npm)")
     .option("--tag <dist-tag|version>", "Override npm dist-tag or version for this update")
     .option("--timeout <seconds>", "Timeout for each update step in seconds (default: 1200)")
@@ -47,6 +48,7 @@ export function registerUpdateCli(program: Command) {
         ["openclaw update --channel beta", "Switch to beta channel (git + npm)"],
         ["openclaw update --channel dev", "Switch to dev channel (git + npm)"],
         ["openclaw update --tag beta", "One-off update to a dist-tag or version"],
+        ["openclaw update --dry-run", "Preview actions without changing anything"],
         ["openclaw update --no-restart", "Update without restarting the service"],
         ["openclaw update --json", "Output result as JSON"],
         ["openclaw update --yes", "Non-interactive (accept downgrade prompts)"],
@@ -69,6 +71,7 @@ ${theme.heading("Switch channels:")}
 ${theme.heading("Non-interactive:")}
   - Use --yes to accept downgrade prompts
   - Combine with --channel/--tag/--restart/--json/--timeout as needed
+  - Use --dry-run to preview actions without writing config/installing/restarting
 
 ${theme.heading("Examples:")}
 ${fmtExamples}
@@ -86,6 +89,7 @@ ${theme.muted("Docs:")} ${formatDocsLink("/cli/update", "docs.openclaw.ai/cli/up
         await updateCommand({
           json: Boolean(opts.json),
           restart: Boolean(opts.restart),
+          dryRun: Boolean(opts.dryRun),
           channel: opts.channel as string | undefined,
           tag: opts.tag as string | undefined,
           timeout: opts.timeout as string | undefined,