feat(cli): show the migration warning on oneshot/linear/project commands

Previously the "other webmux servers detected" nudge only fired in
`webmux project`. Broaden it to the other occasional, server-talking
commands (oneshot, linear) by hoisting the check into the webmux.ts
dispatch — the registry read is cheap and the warning is silent unless
peers actually exist.

Deliberately excludes the high-frequency worktree commands (list/open/
send/…), where a per-invocation warning would be noisy, and `project
migrate` itself (which does the consolidating). Centralizing the call
also removes the now-redundant one in project-commands.ts.

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

Author: hugocasa

bin/src/project-commands.ts

@@ -1,7 +1,7 @@
 import { resolve } from "node:path";
 import { createApi, type ProjectInitPhase, type ProjectInitState } from "@webmux/api-contract";
 import { CommandUsageError, formatServerError } from "./shared";
-import { runMigrate, warnIfOtherInstances } from "./migrate.ts";
+import { runMigrate } from "./migrate.ts";
 
 const PROJECT_SETUP_POLL_INTERVAL_MS = 700;
 const PROJECT_SETUP_TIMEOUT_MS = 5 * 60_000;
@@ -124,9 +124,6 @@ export async function runProjectCommand(args: string[], port: number): Promise<n
     return runMigrate(port);
   }
 
-  // Nudge toward consolidation when other servers are still running.
-  warnIfOtherInstances(port);
-
   const api = createApi(`http://localhost:${port}`);
   try {
     if (parsed.subcommand === "ls") {

bin/src/webmux.ts

@@ -353,6 +353,21 @@ async function main(args: string[] = process.argv.slice(2)): Promise<void> {
     }
   }
 
+  // Nudge toward consolidation when other webmux servers are running — on the
+  // occasional management commands (oneshot/linear/project), but NOT the
+  // high-frequency worktree commands (list/open/send/…) where a per-invocation
+  // warning would be noisy, nor `project migrate` (which consolidates them
+  // itself). Cheap: a local registry read, silent unless peers exist, and to
+  // stderr so it never pollutes piped output.
+  const isProjectMigrate = parsed.command === "project" && parsed.commandArgs[0] === "migrate";
+  const isOccasionalServerCommand = parsed.command === "oneshot"
+    || parsed.command === "linear"
+    || parsed.command === "project";
+  if (isOccasionalServerCommand && !isProjectMigrate) {
+    const { warnIfOtherInstances } = await import("./migrate.ts");
+    warnIfOtherInstances(effectivePort);
+  }
+
   if (parsed.command === "oneshot") {
     const { runOneshotCommand } = await import("./oneshot.ts");
     const exitCode = await runOneshotCommand(parsed.commandArgs, effectivePort);