fix: reject an invalid identity name before offering the creation wizard

src/identityManager.test.ts

@@ -192,8 +192,8 @@ describe("identityManager", () => {
       expect(readActiveIdentity(paths)).toBeUndefined();
     });
 
-    it("throws InvalidIdentityNameError, not a raw ZodError, when the confirmed name fails IdentitySchema's own naming rule", async () => {
-      const prompts = scriptedIdentityPrompts(["create"]);
+    it("throws InvalidIdentityNameError before any prompt appears, not a raw ZodError after the user confirms, when the name fails IdentitySchema's own naming rule", async () => {
+      const prompts = scriptedIdentityPrompts([]);
       await expect(runIdentityWizard(prompts, paths, "joseph.mearman@exadev.io")).rejects.toThrow(
         InvalidIdentityNameError,
       );

src/identityManager.ts

@@ -82,11 +82,16 @@ export function useIdentity(paths: LayoutPaths, name: string): void {
 /**
  * The interactive setup wizard for a new identity, offered by the `@<name>` shortcut and `identity use` when the identity doesn't exist yet and stdin is a real terminal.
  *
+ * Validates `name` against `IdentitySchema`'s own naming rule before any prompt appears — offering "Create it now?" for a name that could never validate (an email address, say, whose `@` the shortcut passes through verbatim) just to fail on confirm is a broken interaction, so an invalid name throws `InvalidIdentityNameError` immediately instead.
+ *
  * Confirms the user wants to create the identity, then optionally creates a default configuration profile (reusing `runProfileWizard`), links them, and sets the identity as active. A cancel at any step writes nothing beyond what was already committed — the identity is only created after the first confirm, and the profile wizard's own cancel handling means a profile-only cancellation still leaves the identity usable. Returns `true` when the identity was created and set active; `false` when the user declined at the initial confirm.
  *
  * Driven entirely by the injected `PromptsPort` so the whole flow is unit-testable with a scripted sequence of answers.
  */
 export async function runIdentityWizard(prompts: PromptsPort, paths: LayoutPaths, name: string): Promise<boolean> {
+  if (!IdentitySchema.safeParse({ name, allowAmbientCredential: false }).success) {
+    throw new InvalidIdentityNameError(name);
+  }
   const choice = await prompts.select({
     message: `No identity named "${name}" exists yet. Create it now?`,
     options: [