fix(telemetry): dedupe plugin_loaded event to once per UTC day

The plugin_loaded event was emitted on every plugin reload, generating
high event volume on PostHog (proportional to opencode restarts per
user per day). With MAU > 60K and active power users restarting
frequently, this drove unnecessary event spend.

Add a separate daily dedup state field (lastPluginLoadedDayUTC) so the
plugin_loaded capture only fires once per UTC day per machine. The
existing daily activity dedup (lastActiveDayUTC, used by
omo_daily_active) is preserved as an independent gate so the two
dimensions cannot overwrite each other in the activity state file.

src/index.ts

@@ -18,6 +18,7 @@ import { installAgentSortShim } from "./shared/agent-sort-shim"
 import { detectExternalSkillPlugin, getSkillPluginConflictWarning } from "./shared/external-plugin-detector"
 import { startBackgroundCheck as startTmuxCheck } from "./tools/interactive-bash"
 import { createPluginPostHog, getPostHogDistinctId } from "./shared/posthog"
+import { getPluginLoadedCaptureState } from "./shared/posthog-activity-state"
 
 const serverPlugin: Plugin = async (input, _options): Promise<Hooks> => {
   installAgentSortShim()
@@ -43,19 +44,27 @@ const serverPlugin: Plugin = async (input, _options): Promise<Hooks> => {
   } catch {
     // telemetry failure is non-fatal, silently ignore
   }
+  let pluginLoadedCaptureState: ReturnType<typeof getPluginLoadedCaptureState> | null = null
   try {
-    posthog.capture({
-      distinctId,
-      event: "plugin_loaded",
-      properties: {
-        entry_point: "plugin",
-        has_openclaw: !!pluginConfig.openclaw,
-        tmux_enabled: isTmuxIntegrationEnabled(pluginConfig),
-      },
-    })
+    pluginLoadedCaptureState = getPluginLoadedCaptureState()
   } catch {
     // telemetry failure is non-fatal, silently ignore
   }
+  if (pluginLoadedCaptureState?.capturePluginLoaded) {
+    try {
+      posthog.capture({
+        distinctId,
+        event: "plugin_loaded",
+        properties: {
+          entry_point: "plugin",
+          has_openclaw: !!pluginConfig.openclaw,
+          tmux_enabled: isTmuxIntegrationEnabled(pluginConfig),
+        },
+      })
+    } catch {
+      // telemetry failure is non-fatal, silently ignore
+    }
+  }
   if (pluginConfig.openclaw) {
     await initializeOpenClaw(pluginConfig.openclaw)
   }