fix: configure state-sync to use locally-restored snapshots

[bdchatham]

Summary

• Local snapshot-aware state-sync: When a node has a locally-restored S3 snapshot, the configure-state-sync task now sets use-local-snapshot = true and derives trust-height from the snapshot height (by scanning data/snapshots/) instead of the chain tip minus 2000. This prevents Tendermint from ignoring the pre-staged snapshot and redundantly fetching all chunks over P2P.
• Parameterized ConfigureStateSyncTask: The controller passes UseLocalSnapshot: true when the SeiNode spec includes a snapshot config (hasLocalSnapshot(node)). The task remains zero-config for nodes without a local snapshot.
• Lint cleanup: Fixes all 24 golangci-lint errcheck violations across the codebase.

Root Cause

The configure-state-sync task was writing use-local-snapshot = false (the default) and deriving trust-height from the chain tip, causing nodes with locally-restored S3 snapshots to perform full P2P state-sync (~4800 chunks over hours) instead of applying the already-present local snapshot.

Changes

File	Change
sidecar/client/tasks.go	Add UseLocalSnapshot field to ConfigureStateSyncTask, wire into params
sidecar/tasks/statesync.go	Branch on useLocalSnapshot param: discover snapshot height from data/snapshots/, set use-local-snapshot in config.toml
sidecar/tasks/statesync_test.go	Add 4 new tests for local snapshot path and height discovery
9 other files	Fix errcheck lint violations (_ = for intentionally-discarded errors)

Test plan

• All existing tests pass (go test ./...)
• golangci-lint run ./... reports 0 issues
• New tests cover: local snapshot config written correctly, missing snapshot dir errors, height discovery picks max, empty dir errors
• Controller change in sei-k8s-controller task_builders.go passes UseLocalSnapshot: hasLocalSnapshot(node) (separate PR)
• Deploy to brandon cluster and verify nodes use local snapshotn