NONEVM-3038: logpoller global filter cache

[jadepark-dev]

Summary

• Add in-memory filter cache (filtersByName) to eliminate redundant DB queries on every poll tick
• Cache is lazily loaded from DB on first access via loadFilters(), then kept in sync by RegisterFilter/UnregisterFilter
• buildFilterIndex and getDistinctAddresses now read from cache instead of hitting DB
• HasFilter returns from cache with no DB round-trip
• RegisterFilter short-circuits on cache hit when filter config is unchanged
• Add GetAllActiveFilters to FilterStore interface with postgres, in-memory, and observed implementations
• Minor formatting cleanup for long function signatures

[Copilot]

Pull request overview

This PR introduces an in-memory filter cache to the logpoller service to eliminate redundant database queries during polling operations. The cache is lazily loaded from the database on first access and kept synchronized through RegisterFilter and UnregisterFilter operations.

Changes:

• Added GetAllActiveFilters method to FilterStore interface with postgres, in-memory, and observed implementations
• Implemented lazy-loading filter cache in service with thread-safe access via filtersMu
• Modified buildFilterIndex and getDistinctAddresses to read from cache instead of querying the database
• Updated RegisterFilter to short-circuit on cache hit when filter configuration is unchanged

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pkg/logpoller/store/postgres/filters.go	Added GetAllActiveFilters to retrieve all non-deleted filters from postgres
pkg/logpoller/store/memory/filters.go	Implemented GetAllActiveFilters for in-memory filter store
pkg/logpoller/service.go	Added filter cache fields, loadFilters helper, and updated processBlockRange signature
pkg/logpoller/observed_filter_store.go	Added metrics wrapper for GetAllActiveFilters
pkg/logpoller/interfaces.go	Extended FilterStore interface with GetAllActiveFilters method
pkg/logpoller/filter_test.go	Added comprehensive test coverage for filter cache behavior
pkg/logpoller/filter.go	Refactored filter operations to use cache with lazy loading

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[huangzhen1997]

Don't need to introduce this var

Suggested change

	f := filters[i]
	lp.filtersByName[f.Name] = &f
	lp.filtersByName[filters[i].Name] = &filters[i]

[huangzhen1997]

Just double check here, the cache check only compares Address/MsgType/EventSig, so another filter with different LogRetention, MaxLogsKept, or StartingSeqNo would be silently skipped. That's intentional right?