Make streaming teardown destructor-safe

[trissim]

Summary

• move Fiji and Napari finalization onto the shared StreamingBackend ownership path
• detach shared-memory, publisher, and context ownership before closing resources so repeated cleanup is idempotent
• avoid module-global logger access during interpreter shutdown while retaining diagnostics for explicit cleanup
• preserve fail-loud behavior for unexpected ownership errors during explicit cleanup

Motivation

OpenHCS Official30 teardown reproduced ignored finalizer exceptions after module globals had begun clearing:

AttributeError: 'NoneType' object has no attribute 'info'

The resource semantics already belong to StreamingBackend; subclass destructors and logger-dependent shutdown paths duplicated that authority and were unsafe during interpreter finalization.

Validation

• 509 passed, 1 skipped across the full local PolyStore suite
• 49 passed across focused streaming cleanup/identity/metadata/receiver/shared-memory/Napari coverage
• Black and Ruff pass on the newly owned shared cleanup implementation and regression test
• git diff --check passes

A dedicated version bump/release will follow only after this PR is green and merged; no published version is reused.