Fix retention query performance and cleanup scheduling

src/lib/server/db/schema.sql

@@ -522,6 +522,7 @@ CREATE TABLE IF NOT EXISTS provisioning_sources (
     server TEXT NOT NULL,
     PRIMARY KEY (operation_id, kind, source_id, server)
 );
+CREATE INDEX IF NOT EXISTS idx_provisioning_sources_source ON provisioning_sources(kind, source_id);
 
 -- Blueprints retain map/count selections only. The legacy column name remains
 -- compatible with older snapshot-based definitions, read as selections at runtime.
@@ -732,6 +733,7 @@ CREATE TABLE IF NOT EXISTS watchdog_actions (
     cycle INTEGER NOT NULL DEFAULT 1,
     UNIQUE(incident_id,cycle,action)
 );
+CREATE INDEX IF NOT EXISTS idx_watchdog_actions_campaign ON watchdog_actions(campaign_id);
 
 -- Explicit history holds and failure resolution never bypass dependency checks.
 CREATE TABLE IF NOT EXISTS retention_controls (