perf(wallet): checkpoint sync persistence

[3esmit]

Summary

• persist wallet state once per 100 processed sync blocks instead of after every block
• persist a final partial batch after a successful stream completes
• cover bounded checkpoints and recovery from an unpersisted account/cursor tail

Root cause

WalletCore::sync_to_block synchronously serialized and fsynced the complete storage snapshot after every streamed block.

Validation

• cargo +nightly fmt --all -- --check
• cargo test -p wallet --lib
• cargo clippy -p wallet --all-targets --all-features -- -D warnings

Closes #31

[3esmit]

Post-fix Testnet verification completed with the compiled branch binary.

Matched 20-second wallet account sync-private replays from isolated cursor-0 wallet states:

Build	Blocks advanced	Persistent writes
main baseline 7227fd3	1,200	1,200
this PR ec954239	6,600	66

Each controlled run reached its timeout normally. A continued branch replay then completed from block 16,800 to live target 42,209 with exit 0: 25,409 blocks and exactly 255 persistent writes (ceil(25,409 / 100)). This validates both checkpointing and the final partial-stream flush.

Also passed locally: cargo fmt --all -- --check, cargo test -p wallet --lib (55/55), and cargo clippy -p wallet --all-targets --all-features -- -D warnings.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: ec95423962

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: d9621778ae

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: b252ca70e9

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[3esmit]

Upstream logos-blockchain#632 is the minimal happy-path optimization: checkpoint every 100 blocks and flush only on successful completion. This PR includes that behavior plus failure-path durability and atomicity safeguards: it flushes partial progress on polling/validation errors and validates a whole block before applying any privacy-state mutation. That makes this PR materially safer under retries/restarts, not just a different implementation style.

[3esmit]

Rebased onto merged main commit 19df384b (PR #37), so the previous deny result no longer reflects the current dependency graph.

Post-rebase local verification passed:

• cargo +nightly fmt --check
• cargo test -p wallet --lib: 58 passed
• wallet Clippy with -D warnings
• cargo deny check: advisories, bans, licenses, and sources all passed

The branch was force-updated to 2fa62b1; GitHub CI is rerunning against the rebased head.

[3esmit]

All required checks are green and review-thread audit shows no unresolved comments. Promoting for merge.

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.
To continue using code reviews, add credits to your account and enable them for code reviews in your settings.