itest: boot piri on Postgres so the stack comes up

Every top-level itest — TestForgeVersity, TestForgeScenarios,
TestForgeNativeProvision, TestForgeReadAfterEviction — failed at stack
boot, not in any assertion:

  Error: initializing piri node: ... ProvideHarmonyDB ...
  curio PDP pipeline requires Postgres (set database type to postgres)

Since piri:main absorbed Curio (~2026-07-24) its PDP pipeline refuses
sqlite, and forgeStack booted sqlite piri via the zero-value
PiriNodeConfig. All four suites route through that one constructor, so
flipping the topology default to Postgres:true is the whole fix; the
pinned smelt already supports it (no dependency bump).

Also relax the CORS preflight status assertion from 200 to any 2xx, the
fetch spec's 'ok status' range. versitygw answers a matched rule 200 and
only its no-CORS-config fallback 204, and the Max-Age assertion is what
actually pins the real path: the fallback sets no Max-Age and mirrors the
requested method instead of the rule's method list. This supersedes the
exact-200 assertion in 900d6b5.

Both changes match what #44 arrived at independently, so the overlap
resolves trivially whichever lands first.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017rwJ8KiPhm3G27vfU21Phk

Author: claude

itest/scenarios_test.go

@@ -290,11 +290,14 @@ func TestForgeScenarios(t *testing.T) {
 			return resp
 		}
 
-		// A matched preflight is answered 200, matching real S3 (browsers
-		// accept any 2xx); 204 is only versitygw's no-CORS-config fallback.
+		// Any 2xx is a successful preflight per the fetch spec; versitygw
+		// answers a matched rule 200 and only its no-CORS-config fallback
+		// 204. The Max-Age assertion below is what pins the real path — the
+		// fallback sets no Max-Age and mirrors the requested method instead
+		// of the rule's method list.
 		resp := preflight(t, origin)
-		if resp.StatusCode != http.StatusOK {
-			t.Errorf("preflight status = %d, want 200", resp.StatusCode)
+		if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+			t.Errorf("preflight status = %d, want 2xx", resp.StatusCode)
 		}
 		if got := resp.Header.Get("Access-Control-Allow-Origin"); got != origin {
 			t.Errorf("preflight Allow-Origin = %q, want the request origin echoed", got)

itest/stack_test.go

@@ -104,7 +104,9 @@ func forgeStack(t *testing.T, extra ...stack.Option) (*stack.Stack, string) {
 	t.Helper()
 	t.Logf("booting the smelt Forge stack (~1-2 min; first run also compiles ingot and pulls images)")
 	opts := []stack.Option{
-		stack.WithPiriNodes(stack.PiriNodeConfig{}),
+		// Postgres-backed piri: piri:main's curio PDP pipeline refuses
+		// sqlite ("curio PDP pipeline requires Postgres") as of 2026-07-24.
+		stack.WithPiriNodes(stack.PiriNodeConfig{Postgres: true}),
 		stack.WithServiceBinary("ingot", localIngotBinary(t)),
 	}
 	// Local-dev escape hatches: run against upload-service (sprue) / piri