Match SHM cache Integration type with sidecar writer

The sidecar's write_shm_file() serializes buffered_integrations as
HashSet<Integration>, but the PHP-side reader in components-rs
deserialized it as HashSet<String>. This mismatch has existed since
the SHM cache was introduced in 91222ad ("feat: reduce telemetry
sent", #3316), but was latent: config_sent was set true before any
integrations appeared in SHM, and integration dedup (the only other
consumer) was silently broken with the sidecar deduplicating
server-side as a fallback.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

components-rs/telemetry.rs

@@ -256,7 +256,7 @@ pub unsafe extern "C" fn ddog_sidecar_telemetry_add_integration_log_buffer(
 
 pub struct ShmCache {
     pub config_sent: bool,
-    pub integrations: HashSet<String>,
+    pub integrations: HashSet<Integration>,
     pub composer_paths: HashSet<PathBuf>,
     pub last_endpoints_push: SystemTime,
     pub reader: OneWayShmReader<NamedShmHandle, CString>,
@@ -314,7 +314,7 @@ unsafe fn ddog_sidecar_telemetry_cache_get_or_update<'a>(
             }
 
             if let Ok((config_sent, integrations, composer_paths, last_endpoints_push)) =
-                bincode::deserialize::<(bool, HashSet<String>, HashSet<PathBuf>, SystemTime)>(buf)
+                bincode::deserialize::<(bool, HashSet<Integration>, HashSet<PathBuf>, SystemTime)>(buf)
             {
                 cache.config_sent = config_sent;
                 cache.integrations = integrations;
@@ -365,7 +365,7 @@ pub unsafe extern "C" fn ddog_sidecar_telemetry_filter_flush(
         .into_iter()
         .filter(|action| match action {
             SidecarAction::Telemetry(TelemetryActions::AddIntegration(integration)) => {
-                !cache_entry.integrations.contains(&integration.name)
+                !cache_entry.integrations.contains(integration)
             }
             SidecarAction::PhpComposerTelemetryFile(path) => {
                 !cache_entry.composer_paths.contains(path)