Change block pruning

[n8mgr]

This fixes a race condition on some nodes when chain subscribers are slow where blocks would be removed from the store before they could be indexed.

[Copilot]

Pull request overview

This PR refactors block pruning from an automatic passive operation (via WithPruneTarget option) to an active manual operation (via PruneBlocks method). The change aims to fix a race condition where blocks were pruned before chain subscribers could index them, by giving integrators explicit control over when pruning occurs.

Changes:

• Removed WithPruneTarget manager option and automatic pruning logic from the chain manager
• Added new PruneBlocks(height) method that allows manual pruning of blocks below a specified height
• Updated sync command to manually call PruneBlocks after each reorg event
• Added test coverage for the new pruning functionality

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
chain/options.go	Removes the WithPruneTarget option function
chain/manager.go	Removes automatic pruning from applyTip and adds new PruneBlocks method for manual pruning
internal/cmd/sync/main.go	Updates reorg channel to pass ChainIndex and calls PruneBlocks manually after each reorg
internal/cmd/calcswaps/main.go	Removes usage of WithPruneTarget option
chain/db_test.go	Adds test for the new PruneBlocks functionality
.changeset/*.md	Documents the breaking change with appropriate version bump

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[peterjan]

Looks good to me!