feat(archive): keep page open on captcha-status errors so callers can promote

Adds OpenPageOptions.AllowNonOKStatus. When set, openPage no longer closes
the page on non-2xx (other than 404) and Open returns both a usable Document
and ErrInvalidStatusCode. archive.IsArchived and Archive opt in, so callers
can PromoteToInteractive the captcha page, hand it to a human solver, and
demote back to extract content from the same browser instance — avoiding
the cf_clearance fingerprint-binding issue that re-challenges any fresh
retry browser.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

browser.go

@@ -7,6 +7,14 @@ import (
 
 type OpenPageOptions struct {
 	Referer string
+
+	// AllowNonOKStatus, when true, keeps the page open and returns a usable
+	// Document along with ErrInvalidStatusCode on non-2xx responses (other
+	// than 404, which is treated as ErrPageNotFound and still closes the
+	// page). This lets callers promote the page to an InteractiveBrowser
+	// to e.g. let a human solve a Cloudflare captcha that produced a 403,
+	// then resume extraction from the same browser instance.
+	AllowNonOKStatus bool
 }
 
 type Browser interface {