feat(triggers): show a materialized column in pic triggers ls --app (D1)

A materialized copy of an M5 group stateful template (cron/queue/email) now
reads as `materialized = true` — inherited, read-only — distinct from a
hand-authored trigger. Threads a derived `materialized` bool (=
`materialized_from IS NOT NULL`) row → domain → API → CLI, mirroring the
`sealed`/`shared` columns; `list_for_app` SELECTs `materialized_from`. No
migration.

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

crates/picloud-cli/src/client.rs

@@ -1760,6 +1760,11 @@ pub struct TriggerDto {
     pub enabled: bool,
     pub dispatch_mode: String,
     pub retry_max_attempts: u32,
+    /// §4.5 M5: true for a materialized copy of a group stateful template
+    /// (inherited, read-only). `default` so an older server without the field
+    /// still deserializes.
+    #[serde(default)]
+    pub materialized: bool,
     pub created_at: DateTime<Utc>,
     #[serde(default)]
     pub details: Value,