Add --account N flag and fix credential priority in Erlang, Elixir, OCaml, F#, Haskell SDKs
Correct 5-tier credential priority across all five implementations:
1. Explicit -p/-k flags (function arguments)
2. --account N -> accounts.csv row N (bypasses env vars)
3. UNSANDBOX_PUBLIC_KEY / UNSANDBOX_SECRET_KEY env vars
4. ~/.unsandbox/accounts.csv row 0 (or UNSANDBOX_ACCOUNT env)
5. ./accounts.csv row 0
Erlang: add load_credentials_from_csv/2, extract_account_arg/3,
process-dict-based account_index, dispatch/1 helper, fix get_api_keys/0.
Elixir: add load_credentials_from_csv/2, extract_account_arg/3,
Process.put/get-based account_index, dispatch/1 helper, fix get_api_keys/0.
OCaml: add cli_account_index ref, parse_accounts_csv, load_csv_at,
strip_account_arg, fix get_credentials priority ordering.
F#: add AccountIndex field to Args, loadCredentialsFromCsv, fix getApiKeys
signature to accept accountIndex, wire --account N in parseArgs.
Haskell: add cliAccountIndex IORef (unsafePerformIO), loadCredentialsFromCsv,
stripAccountArg, fix getApiKeys priority ordering.
russell@unturf.com
13f15c8abc