fix(nodes): "Invalid input" when saving a node with inbound sync mode "all"

NodeFormSchema required inboundTags, but the inboundTags Form.Item is only
mounted when inboundSyncMode is "selected" - antd onFinish omits unmounted
fields, so saving with the default "all" mode failed schema validation with
Zod generic "Invalid input" (regression from #5178; same class as the
earlier pinnedCertSha256 fix).

Also tolerate null inboundTags (Go nil slice) for nodes saved before #5178,
both in the form schema and NodeRecordSchema, and normalize edit-mode values.

.gitignore

@@ -36,6 +36,7 @@ Thumbs.db
 x-ui.db
 x-ui.db-shm
 x-ui.db-wal
+system_metrics.gob
 *.dump
 
 # Ignore Docker specific files