fix: preserve ApiError type in Seer error handler + suggest trial start command

Two fixes for the highest-impact error classes:

1. handleSeerApiError: return ApiError instead of plain Error for
   non-Seer API failures (CLI-N, 84 users). Previously, unrecognized
   403s and 500s from the Seer endpoint became plain Error objects,
   losing status code and endpoint info. Now preserves them as ApiError.

2. SeerError.format(): suggest 'sentry trial start seer <org>' instead
   of passive 'sentry trial list' when org is known (CLI-1D/BW/98,
   237 users combined). The interactive trial prompt in bin.ts requires
   isatty(0) which is false for AI agents and CI — the most common
   callers of issue explain/plan. The direct command gives non-interactive
   users an actionable next step they can copy-paste.

Author: BYK

src/lib/errors.ts

@@ -404,11 +404,14 @@ export class SeerError extends CliError {
   }
 
   override format(): string {
-    // Soften trial hint — we can't check availability synchronously,
-    // so use "check" language rather than "start" to avoid misleading
-    // users whose trial is already expired
-    const trialHint =
-      "\n\nYou may be eligible for a free trial:\n  sentry trial list";
+    // When org slug is known, suggest the direct trial start command.
+    // The interactive trial prompt in bin.ts handles TTY users; this
+    // message is the fallback for non-interactive contexts (AI agents, CI)
+    // where the prompt can't fire — hence the direct command suggestion
+    // (CLI-1D/BW/98, 237 users combined).
+    const trialHint = this.orgSlug
+      ? `\n\nStart a free trial:\n  sentry trial start seer ${this.orgSlug}`
+      : "\n\nYou may be eligible for a free trial:\n  sentry trial list";
 
     // When org slug is known, provide direct URLs to settings
     if (this.orgSlug) {

src/lib/formatters/seer.ts

@@ -10,7 +10,7 @@ import type {
   RootCause,
   SolutionArtifact,
 } from "../../types/seer.js";
-import { SeerError } from "../errors.js";
+import { ApiError, SeerError } from "../errors.js";
 import { cyan } from "./colors.js";
 import { escapeMarkdownInline, renderMarkdown } from "./markdown.js";
 
@@ -195,12 +195,17 @@ export function createSeerError(
 }
 
 /**
- * Convert an API error to a Seer-specific error or a generic error.
+ * Convert an API error to a Seer-specific error or an ApiError.
+ *
+ * Returns a SeerError for known Seer issues (402/403 with specific detail),
+ * or preserves the error as an ApiError for other failures. Previously
+ * returned a plain Error which lost the status code and endpoint — causing
+ * CLI-N (84 users) where unrecognized 403s became untyped errors.
  *
  * @param status - HTTP status code
  * @param detail - Error detail from API
  * @param orgSlug - Organization slug for constructing settings URLs
- * @returns SeerError for Seer-specific errors, or a generic Error for other API errors
+ * @returns SeerError for Seer-specific errors, or ApiError for other API errors
  */
 export function handleSeerApiError(
   status: number,
@@ -211,7 +216,7 @@ export function handleSeerApiError(
   if (seerError) {
     return seerError;
   }
-  return new Error(formatAutofixError(status, detail));
+  return new ApiError(formatAutofixError(status, detail), status, detail);
 }
 
 /**