config(state-sync): hide tendermint tuning knobs from template

[blindchaser]

Summary

Trim the rendered [statesync] section in sei-tendermint/config/toml.go so newly generated config.toml files show only the operator-facing state sync settings. Hidden settings are still parsed from existing config files, so upgraded nodes keep their current behavior.

• Hidden from newly generated config.toml: backfill-blocks, backfill-duration, discovery-time, temp-dir, chunk-request-timeout, fetchers, verify-light-block-timeout, and blacklist-ttl.

• Kept in newly generated config.toml: enable, use-p2p, rpc-servers, trust-height, trust-hash, trust-period, and use-local-snapshot.

• Kept in generated app.toml: snapshot-interval, snapshot-keep-recent, and snapshot-directory. snapshot-keep-recent remains visible because operators commonly tune it for snapshot retention and disk usage.

• sei-tendermint/config/toml.go: removes the eight tuning keys above from the rendered template and replaces their old per-key comments with one grouped comment that still names every hidden key.

• sei-tendermint/config/toml_test.go: verifies the rendered template no longer contains assignments for the hidden keys.

• sei-tendermint/config/statesync_compat_test.go: verifies hidden keys still parse when present in an existing config.toml, and verifies a fresh config without those keys uses DefaultStateSyncConfig() values and passes ValidateBasic().

Test plan

• sei-tendermint/config/toml_test.go: checkConfig rejects rendered assignments for backfill-blocks, backfill-duration, discovery-time, temp-dir, chunk-request-timeout, fetchers, verify-light-block-timeout, and blacklist-ttl. configContainsKey avoids prefix false positives such as fetchers matching a longer key.
• sei-tendermint/config/statesync_compat_test.go: TestHiddenStateSyncKnobsStillParseFromExistingConfig writes all hidden keys into a config file and asserts commands.ParseConfig populates the corresponding StateSyncConfig fields.
• sei-tendermint/config/statesync_compat_test.go: TestFreshStateSyncConfigValidatesWithoutHiddenKnobs writes a fresh-style config without hidden keys, asserts omitted fields come from DefaultStateSyncConfig(), and asserts cfg.StateSync.ValidateBasic() succeeds.
• Validation run locally: go test ./config/... -run 'TestConfig|TestHiddenStateSync|TestFreshStateSync' -count=1 -timeout 180s from sei-tendermint.

[github-actions]

The latest Buf updates on your PR. Results from workflow Buf / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	May 8, 2026, 8:52 AM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.15%. Comparing base (c7e729a) to head (1cf5f35).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3352      +/-   ##
==========================================
- Coverage   59.17%   59.15%   -0.03%     
==========================================
  Files        2108     2097      -11     
  Lines      173660   172028    -1632     
==========================================
- Hits       102770   101755    -1015     
+ Misses      62008    61425     -583     
+ Partials     8882     8848      -34     

Flag	Coverage Δ
sei-chain-pr	70.96% <ø> (?)
sei-db	70.41% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
sei-tendermint/config/toml.go	55.00% <ø> (ø)

... and 118 files with indirect coverage changes

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[masih]

Thank @blindchaser and sorry it took me so long to review this one.

Left a question that we might need to address before cutting the next release; not a blocker and totally fine to approach in a separate PR if needed 🍻

[masih]

This is good but how the code on the latest version behave when these configs are still present?
This is likely the case for most nodes, where they upgrade the binary but rarely change the config.

[blindchaser]

Backward compatible: only the rendered template hides these keys. The StateSyncConfig struct fields and their mapstructure tags (backfill-blocks, backfill-duration, discovery-time, temp-dir, chunk-request-timeout, fetchers, verify-light-block-timeout, blacklist-ttl) are unchanged, so existing config.toml files continue to parse and honor those values exactly as before.

Covered by TestHiddenStateSyncKnobsStillParseFromExistingConfig in sei-tendermint/config/statesync_compat_test.go (existing config path) and TestFreshStateSyncConfigValidatesWithoutHiddenKnobs (fresh config falls back to DefaultStateSyncConfig() defaults).