Cardano Updates

Remove redundant idx_transaction_block_hash_tx_index index as the existing idx_transaction_slot_desc_tx_index_desc already provides efficient query performance for block transaction retrieval with proper ordering.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

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

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

- Remove '|| true' from .github/workflows/nilaway.yml to fail CI on nil errors
- Add nil checks in connmanager/listener.go for EventBus operations
- Fix unsafe type assertions and add nil checks in ledger/state.go
- Add defensive nil checks in database/plugin/metadata/sqlite/account.go
- Add nil checks for PrimaryChain() results in chain/manager.go and chain/chain.go
- Add comprehensive nil safety to all major Chain methods
- Add nil checks in database/block.go, peergov/*.go, utxorpc/submit.go
- Add nil check in internal/node/load.go for GetTip() result

Resolves potential nil pointer dereferences across 11 files identified by
static analysis, improving code robustness and preventing runtime panics.

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

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

- Replace hard-coded blockfetchBatchSlotThreshold with dynamic calculation
- Use correct security parameters based on current era:
  * Byron era: K parameter from ByronGenesis.ProtocolConsts.K
  * Shelley+ eras: SecurityParam from ShelleyGenesis.SecurityParam
- Update stability window calculation in both chainsync and validation logic
- Calculate stability window as 3k/f for Shelley+ eras, k for Byron era
- Ensures blockfetch operations respect protocol-defined stability window

Fixes the TODO to calculate slot threshold from protocol params

Signed-off-by: Chris Gianelloni <[email protected]>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

extend fail-fast error detection to cosmos sidechain startup in caribic CLI

Signed-off-by: Hyperledger Bot <[email protected]>

Signed-off-by: Hyperledger Bot <[email protected]>

- Add nil check for PrimaryChain() result before dereferencing
- Resolves nilaway error at chain/chain.go:368:20 and 474:20

* adds dates

* adds onboarding

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