fix(cache,da): drop finalized snapshot entries on restore and drain DA subscription channel

[tac0turtle]

Overview

Two memory fixes for long-running nodes, found while investigating a user report of sustained memory growth (+201 MiB/min) and OOM kills on syncing nodes.

1. Cache restore leaks stale placeholders across crash/restart cycles

The DA-inclusion snapshot is only persisted on graceful shutdown (Components.Stop). After a crash (e.g. OOM kill, SIGKILL), the node restores a snapshot from the last graceful shutdown, which can contain heights already at or below the persisted DAIncludedHeight watermark. Since:

• the inclusion loop only calls DeleteHeight for heights it advances through, and
• IsHeightDAIncluded short-circuits true below the watermark so those entries are never consulted,

restored placeholders below the watermark were never evicted, and were re-persisted on the next graceful save — so the snapshot grew monotonically across crash/restart cycles.

Cache.RestoreFromStore now takes the finalized height and skips entries at or below it. Skipped entries still contribute to maxDAHeight, so DaHeight() semantics are unchanged. manager.RestoreFromStore reads DAIncludedHeightKey and passes it through; a read error falls back to unfiltered restore instead of failing startup.

The pre-existing comment in TestManager_SaveAndRestoreFromStore already described this as the intended behavior ("The cache entry is not restored — this is correct and intentional") — the code just didn't do it. It now does, and the test asserts it.

2. DA subscription goroutine leak on reconnect

The client.Subscribe wrapper goroutine exited on ctx cancellation without draining the underlying jsonrpc channel. The go-jsonrpc delivery goroutine blocked on send into that channel never observed the cancellation and never closed its channel — leaking one goroutine per watchdog reconnect (observed in the field as Subscribe.func1 goroutines doubling). The wrapper now drains the raw channel on exit, matching what its own doc comment previously required of callers.

Testing

• New TestCache_RestoreFromStore_SkipsFinalizedEntries covering partial and fully-stale snapshots
• TestManager_SaveAndRestoreFromStore now asserts finalized heights are not restored
• go test ./block/..., go vet, golangci-lint all clean

Note: this does not address the primary OOM driver from the same investigation (unbounded pendingEvents buffering when DA catchup outpaces execution) — that needs a separate backpressure change.

🤖 Generated with Claude Code

[coderabbitai]

Caution

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch marko/cache-restore-filter-sub-drain

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[github-actions]

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

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	⏩ skipped	✅ passed	⏩ skipped	Jul 15, 2026, 1:41 PM

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.32%. Comparing base (e437a62) to head (b769abd).

Files with missing lines	Patch %	Lines
block/internal/cache/manager.go	16.66%	2 Missing and 3 partials ⚠️
block/internal/da/client.go	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3385      +/-   ##
==========================================
- Coverage   62.33%   62.32%   -0.01%     
==========================================
  Files         120      120              
  Lines       13425    13433       +8     
==========================================
+ Hits         8368     8372       +4     
- Misses       4118     4120       +2     
- Partials      939      941       +2     

Flag	Coverage Δ
combined	62.32% <50.00%> (-0.01%)	⬇️

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