fix(ux): remove -n short flag from spawn link --name to prevent silent conflict (#2822)

The top-level arg parser in index.ts:820 claims -n for --dry-run before
any subcommand sees it. Running `spawn link 1.2.3.4 -n my-server` silently
drops the intended name value — the user gets no error, the spawn is
registered without the name they specified.

Removing -n from link's --name extractFlag call eliminates the conflict.
The --name long form is unaffected and documented in the usage string.

Also updates cmd-link-cov.test.ts to use --name in the short-flags test.

Agent: ux-engineer

Co-authored-by: B <6723574+louisgv@users.noreply.github.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/cli/src/__tests__/cmd-link-cov.test.ts

@@ -209,7 +209,7 @@ describe("cmdLink (additional coverage)", () => {
         "sprite",
         "-u",
         "ubuntu",
-        "-n",
+        "--name",
         "my-box",
       ],
       {

packages/cli/src/commands/link.ts

@@ -200,7 +200,6 @@ export async function cmdLink(args: string[], options?: LinkOptions): Promise<vo
   remaining = r3;
   const [nameFlag, r4] = extractFlag(remaining, [
     "--name",
-    "-n",
   ]);
   remaining = r4;