Cardano Updates

Signed-off-by: Chris Gianelloni <[email protected]>

HLS 2.9.0.0 doesn't support GHC 9.8.4. Update tools index-state
to 2026-01-20 to get HLS 2.13.0.0 which has GHC 9.8.4 support.

Replace head with pattern matching or safe alternatives in:
- db-bench.hs (benchmark labels)
- Integration tests: Byron/Migrations, Shared/Transactions,
  Shared/Wallets, Shelley/Addresses, Shelley/Migrations,
  Shelley/StakePools, Shelley/Transactions, Shelley/TransactionsNew,
  Shelley/Wallets

Replace head/tail partial functions with pattern matching or NonEmpty
alternatives in test files to avoid -Wx-partial warnings becoming errors
with -Werror.

- Add DuplicateRecordFields to Cardano.Write.Tx
- Replace partial functions in CommandLine.hs and BalanceSpec.hs

Replace head with pattern matching or safe alternatives in:
- SlottingSpec.hs
- RangeSpec.hs
- Discovery.hs

GHC 9.8.4 requires this extension when exporting types
with duplicate field names.

GHC 9.8.4 warns about head/tail as partial functions.
Also remove Ord from TxChange since TokenMap doesn't support Ord.

GHC 9.8.4 warns about head as a partial function.

GHC 9.8.4 warns about head as a partial function.

GHC 9.8.4 warns about head/tail as partial functions.
Replace tail with drop 1 and head with explicit pattern matching.

HLS 2.13.0.0 supports GHC 9.8.4.

Signed-off-by: Chris Gianelloni <[email protected]>

MDX parses components inside HTML comments, causing build failures.
Remove SingleDocker126/127 tab items and commented imports since
the single-docker.md files were previously deleted.