Testing: Miner scenarios

- [x] Window PoSt block
- Blocks with window post should be accepted by others nodes. It means that our sectors are accepted by the net.
- [x] Winning PoSt block
- [x] Pledge sector
- [x] 32 GiB sector sealing
- [x] Turn down the node, turn it on and continue sealing
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- [x] Storage Deal and Retrieval Deal
- One storage and one retrieval deal
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- [x] Many simultaneous deals
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- [x] Several in a row (in one sector)
- Stress test - many in one moment, check where the boundaries are
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- [x] Fast Retrieval
- Check if miner works correctly with "Fast retrieval" flag

No source file, test, or entry point is named, so begin by locating the existing miner scenario or integration-test entry points and comparing them with this checklist. Completion cannot be determined from the issue alone; the listed scenarios should be traceable to runnable coverage, including restart, deals, concurrent deals, and fast retrieval.

Written by the indexing model from the issue text.