chore: import upstream snapshot with attribution

apps/sim/lib/posthog/client.ts

@@ -0,0 +1,46 @@
+import type { PostHog } from 'posthog-js'
+import type { PostHogEventMap, PostHogEventName } from '@/lib/posthog/events'
+
+/**
+ * Capture a client-side PostHog event from a non-React context (e.g. Zustand stores).
+ *
+ * Uses the same dynamic `import('posthog-js')` pattern as `session-provider.tsx`.
+ * Fully fire-and-forget — never throws, never blocks.
+ *
+ * React components should use {@link captureEvent} with the `posthog` instance from `usePostHog()`.
+ *
+ * @param event      - Typed event name from {@link PostHogEventMap}.
+ * @param properties - Strongly-typed property bag for this event.
+ */
+export function captureClientEvent<E extends PostHogEventName>(
+  event: E,
+  properties: PostHogEventMap[E]
+): void {
+  import('posthog-js')
+    .then(({ default: posthog }) => {
+      try {
+        if (typeof posthog.capture === 'function') {
+          posthog.capture(event, properties)
+        }
+      } catch {}
+    })
+    .catch(() => {})
+}
+
+/**
+ * Typed wrapper for `posthog.capture` in React components.
+ *
+ * Enforces event names and property shapes from {@link PostHogEventMap} at compile time,
+ * matching the type safety provided by `captureServerEvent` on the server side.
+ *
+ * @param posthog    - PostHog instance from `usePostHog()`.
+ * @param event      - Typed event name from {@link PostHogEventMap}.
+ * @param properties - Strongly-typed property bag for this event.
+ */
+export function captureEvent<E extends PostHogEventName>(
+  posthog: PostHog | null | undefined,
+  event: E,
+  properties: PostHogEventMap[E]
+): void {
+  posthog?.capture(event, properties as Record<string, unknown>)
+}