feat(migrate): onboarding backfill (repositories + dast_targets -> onboarded_targets) (#141)

compliance-agent/src/database.rs

@@ -179,6 +179,23 @@ impl DatabasePool {
             .collect())
     }
 
+    /// Tenant ids for every provisioned tenant database, derived by stripping
+    /// the `<prefix>_` from the database names. Skips the admin database
+    /// (`<prefix>__admin`). Hash-fallback names (very long tenant_ids) are lost
+    /// at the cluster level and cannot be recovered here — in practice tenant
+    /// ids are UUIDs and never hit that path. Used by the migration CLI's
+    /// `--all` mode.
+    pub async fn list_tenant_ids(&self) -> Result<Vec<String>, AgentError> {
+        let prefix = format!("{}_", self.db_prefix);
+        Ok(self
+            .list_tenant_db_names()
+            .await?
+            .into_iter()
+            .filter_map(|n| n.strip_prefix(&prefix).map(str::to_string))
+            .filter(|id| !id.starts_with('_'))
+            .collect())
+    }
+
     /// Drop the database for a specific tenant. Used by GDPR delete
     /// and tenant offboarding. Idempotent — dropping a non-existent
     /// database is a no-op at the driver level.
@@ -521,6 +538,13 @@ impl Database {
         self.inner.collection("onboarded_targets")
     }
 
+    /// A typed handle to an arbitrary collection by name. For bookkeeping
+    /// collections without a dedicated model (e.g. `schema_migrations`,
+    /// `onboarding_migration_log`).
+    pub fn collection_named<T: Send + Sync>(&self, name: &str) -> Collection<T> {
+        self.inner.collection(name)
+    }
+
     pub fn dast_scan_runs(&self) -> Collection<DastScanRun> {
         self.inner.collection("dast_scan_runs")
     }