* filer: keep .system internal folder in the default SQL table
Bucket-table SQL stores read the first path segment under /buckets as a
bucket name. The ListBuckets owner index lives at /buckets/.system/..., so
every write there hit isValidBucket(".system") == false and returned
"invalid bucket name .system", flooding the filer log on the postgres/mysql
backends. Route dot-prefixed internal folders to the default table by their
full path, like any other non-bucket entry.
* filer: keep .system internal folder in the default leveldb3 DB
Same guard as the SQL stores: leveldb3 would otherwise open a separate DB
for the .system owner-index folder instead of keeping it in the default DB.
* filer: keep .system internal folder under the default ydb prefix
Skips a DescribeTable round trip per operation on the .system owner-index
path, which never resolves to a real bucket table.
* filer: keep .system internal folder in the default arangodb collection
Avoids creating a stray collection for the .system owner-index folder.
* cassandra2: default connection_timeout_millisecond so env-var configs keep the 600ms timeout
The scaffold documents a 600ms default, but the value has no SetDefault. A
config supplied purely through env vars (or a minimal toml) that omits the
key read back 0, silently overriding the client timeout with no bound.
* ydb: default the table path prefix so env-var configs keep the seaweedfs sub-path
The scaffold documents prefix = "seaweedfs", but with no SetDefault a config
that omits it lands tables at the database root instead of under seaweedfs/.
* fix(ydb): table creation with params
* fix(ydb): migrate to new query client & prevent creation table-bucket on get request
* fix(ydb): use new query client with kv req
* fix(ydb): use directory in every query
* fix(ydb): del unused import
* fix(ydb): tests & default const usage
Chris Lu