fix(supermemory): honor auto capture across lifecycle flushes

[CryptoKylan]

Summary

Fixes an auto_capture: false policy leak in the bundled Supermemory provider.

The provider already respected the flag in sync_turn(), but three independent automatic lifecycle flushes bypassed it:

• gateway transcript ingest through on_session_end() (including compaction/session boundaries),
• buffered turn flush through on_session_switch(), and
• the process-termination fallback flush.

All three now honor the same flag. Explicit user-intent writes through supermemory_store and on_memory_write() remain available when automatic capture is disabled.

This is a narrower lifecycle-complete follow-up to #21690 / #21692.

Validation

python -m pytest tests/plugins/memory/test_supermemory_autocapture_guard.py tests/plugins/memory/test_supermemory_provider.py -o 'addopts=' -q\n34 passed in 5.04s\n\nruff check plugins/memory/supermemory/__init__.py tests/plugins/memory/test_supermemory_autocapture_guard.py\nAll checks passed!\n\npython -m py_compile plugins/memory/supermemory/__init__.py\ngit diff --check\n```\n\nThe regression suite covers disabled and enabled behavior at each lifecycle boundary, repeated session-end calls representative of compression, and preservation of explicit tool and memory-write paths.

[CryptoKylan]

Marked ready after independent, provenance-verified Opus 5 review of the final diff.

Review result: pass_with_watchlist, high confidence, no blocking defects. The one behavioral finding (disabled session-switch path did not reset _turn_count) was fixed with a failing regression first; the review was then rerun against amended commit fbe45db679.

Final validation:

python -m pytest tests/plugins/memory/test_supermemory_autocapture_guard.py tests/plugins/memory/test_supermemory_provider.py -o 'addopts=' -q\n34 passed\n\nruff check plugins/memory/supermemory/__init__.py tests/plugins/memory/test_supermemory_autocapture_guard.py\nAll checks passed!\n\npython -m py_compile plugins/memory/supermemory/__init__.py\ngit diff --check\n```\n\nNon-blocking watchlist: `auto_capture` intentionally governs automatic storage, while `auto_recall` independently controls recall/network queries; this follow-up deliberately does not alter that documented policy boundary.

[CryptoKylan]

Status correction: GitHub is still serving the pre-amend head 7ed8909f for this PR, even though the source branch now resolves to independently reviewed commit fbe45db679. I returned the PR to draft while resolving that fork/PR synchronization mismatch; please do not review it yet.

[CryptoKylan]

Superseded by #78656. GitHub kept this PR pinned to stale commit 7ed8909f after the reviewed amendment; #78656 is the identical reviewed change from a fresh branch and correctly points to fbe45db679.

[CryptoKylan]

Closing as superseded by #78656 to avoid reviewers landing on the stale fork head.

[alt-glitch]

This was generated by AI during triage.

@Dhravya @MaheshtheDev Tagging you on this Supermemory provider item as the soft maintainers.