test: add wallet creation SQLite lifecycle coverage

[j-kon]

Summary

• add deterministic offline SQLite lifecycle/persistence coverage for fresh wallet creation
• persist external and internal derivation state, dispose the original resources, and reload with a new persister
• verify network, zero balance, derivation indexes, and address scripts after reopening
• keep this coverage in the normal offline test suite under test/
• reuse the repository cleanup retry pattern for cross-platform SQLite file handling

Closes #93

Why

Existing tests cover wallet constructors, loading a prebuilt SQLite fixture, and broad randomized or live-network flows. This adds focused offline coverage for the create-to-persist-to-reload lifecycle against a previously nonexistent SQLite database.

Validation

• dart format --output=none --set-exit-if-changed lib test example
• dart analyze --fatal-infos --fatal-warnings lib test example
• dart test test/wallet_creation_sqlite_lifecycle_test.dart
• dart test (26 passed, 5 live-network tests skipped by their environment gate)

[reez]

This seems like a good idea I think.

[Johnosezele]

i'm still looking at this, though upon first glance I don't know if your intention is for this to be an integration test or simple offline persistence test... our test/integration/ suite are env-gated readme, this file lives there and carry the integration tag but isn't. I'd like some clarity on this before proceeding to review.

[j-kon]

Updated this based on the review feedback.

The SQLite wallet creation lifecycle coverage has been moved out of test/integration/ and now lives in the normal offline test suite as test/wallet_creation_sqlite_lifecycle_test.dart.

I also removed the integration tag and updated the PR wording to describe this as offline SQLite lifecycle/persistence coverage rather than live env-gated integration coverage.

Validation run:

• dart format --output=none --set-exit-if-changed lib test example
• dart analyze --fatal-infos --fatal-warnings lib test example
• dart test test/wallet_creation_sqlite_lifecycle_test.dart
• dart test

[j-kon]

Updated the SQLite lifecycle coverage with another cleanup pass.

Changes:

• removed the unrelated generated lib/bdk.dart whitespace diff
• tightened native resource cleanup based on the repository’s existing FFI disposal patterns
• reduced repetitive lifecycle cases so the test remains focused on issue test: add wallet creation SQLite lifecycle integration coverage #93
• renamed the remaining tests to describe the behavior being verified

The test remains deterministic and offline under the normal test/ suite.

Validation:

• dart format --output=none --set-exit-if-changed lib test example
• dart analyze --fatal-infos --fatal-warnings lib test example
• dart test test/wallet_creation_sqlite_lifecycle_test.dart
• dart test