Resolve all 46 low-severity architecture review findings

docker/site-a-node-a/appsettings.Site.json

@@ -27,26 +27,12 @@
         "ProbeConnectTimeoutMs": 1000
       }
     },
-    "Database": {
-      // Migration-only as of LocalDb Phase 2. The site config tables now live in the
-      // consolidated LocalDb database (LocalDb:Path). SiteDbPath is read once at boot to drain
-      // a pre-Phase-2 scadabridge.db, and is unused after that - keep it until this node has
-      // started once.
-      "SiteDbPath": "/app/data/scadabridge.db"
-    },
     "DataConnection": {
       "ReconnectInterval": "00:00:05",
       "TagResolutionRetryInterval": "00:00:10",
       "WriteTimeout": "00:00:30",
       "SeedReadTimeout": "00:00:30"
     },
-    "StoreAndForward": {
-      // Migration-only as of LocalDb Phase 2. The store-and-forward buffer now lives in the
-      // consolidated LocalDb database (LocalDb:Path) as the replicated sf_messages table.
-      // SqliteDbPath is read once at boot by SiteLocalDbLegacyMigrator to drain a pre-Phase-2
-      // file, and is unused after that - keep it until this node has started once.
-      "SqliteDbPath": "/app/data/store-and-forward.db"
-    },
     "Communication": {
       // DEV-ONLY control-plane preshared key — NOT a real secret. Must be
       // IDENTICAL on both nodes of the pair and match the central-side entry in