Shuts down the singleton DuckDB connection to release file locks, then
recreates it so the session keeps working. The new connection gets the
same macro/R-function setup that duckplyr normally does on first access.
Usage
shutdown_and_reset_singleton()
Value
TRUE on success, FALSE on failure.
Details
We replace $con directly instead of setting it to NULL because duckplyr
stacks reg.finalizer(onexit = TRUE) calls that accumulate across resets.
If $con is NULL when those finalizers fire at session exit, each one
calls dbDisconnect(NULL) and errors. Keeping a valid connection avoids
that.
Note
This accesses duckplyr internals (default_duckdb_connection and
create_default_duckdb_connection). Validated against duckplyr 0.4.1.
If duckplyr changes these internals the function returns FALSE and the
caller falls back to the warning path.
