feat(archive): capture all PostHog resource modules to DB + MinIO

Extends archival beyond events/persons/cohorts. New generic resource
archiver (posthog-resource-archive@*/6h) snapshots surveys, feature flags,
experiments, dashboards, insights, annotations, and actions into
posthog_resource_snapshots — change-detected (hash over non-volatile config),
lossless `data` payload — and dumps a full per-type daily copy to MinIO
(resources/<type>/<date>.json.gz). listResource() pages any PostHog REST
resource. Survey responses + flag calls are already captured as events.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/prisma/schema.prisma

@@ -538,6 +538,29 @@ model PosthogCohortSnapshot {
   @@map("posthog_cohort_snapshots")
 }
 
+// Generic change-history of every PostHog "resource" module beyond events:
+// surveys, feature_flags, experiments, dashboards, insights, annotations,
+// actions. One row is appended only when a resource's config changed
+// (stateHash compare); the full payload is kept lossless in `data`, and a full
+// per-type daily snapshot is also dumped to MinIO. Survey responses + flag
+// calls are events (already in posthog_events) — this captures the definitions.
+model PosthogResourceSnapshot {
+  id           String    @id @default(cuid())
+  projectKey   String
+  resourceType String // survey | feature_flag | experiment | dashboard | insight | annotation | action
+  resourceId   String // PostHog resource id (stringified)
+  name         String?
+  stateHash    String // change-detection over the non-volatile config
+  data         Json // full resource payload, lossless
+  capturedAt   DateTime  @default(now())
+  dumpedAt     DateTime?
+
+  @@index([projectKey, resourceType, capturedAt])
+  @@index([resourceType, resourceId, capturedAt])
+  @@index([dumpedAt])
+  @@map("posthog_resource_snapshots")
+}
+
 // ---------- Phase C: Sentry archive ----------
 
 // Sentry issue (group) aggregate state. Upserted to the latest snapshot — the