fix(python): retain memory event filters across reconnects - #1145

Summary

MemoryEventClient stopped sending patterns, scope, and scope_id after a dropped connection or an initial failure followed by subscribe(). Snapshot the explicit connection parameters and reuse them for background connections, while preserving explicit connect() defaults.

Rebased onto current main after #1142 landed. Subscription-initiated connections retain the filters and use the shutdown fix's tracked background tasks, so closing the client can cancel them. Both sets of memory-event regressions pass together.

Prepared with AI assistance, independently reviewed and tested.

Type of change

• Bug fix

Test plan

• Real local WebSocket regressions for disconnects, initial connection failure, caller list mutation, connected no-op calls, and explicit unfiltered connections; shutdown and reconnect tests run together.
• Python SDK Ruff and mypy checks.
• ./scripts/test-all.sh (control plane, Go SDK, Python SDK with unchanged default coverage/markers, TypeScript SDK, and web UI). Go uses an isolated Linux Go 1.25.14 runtime with controlled public/invalid DNS; Python 3.12 and JavaScript run natively on macOS.
• Memory event tests with websockets 12.0 and 15.0.1.
• Python benchmark from .github/workflows/memory-metrics.yml.
• make fmt tidy completed. Unrelated baseline formatter changes were restored; the two PR files already match the formatter and module files were unchanged.

Test coverage

• No coverage baselines were lowered.
• New code paths are covered by tests.
• CI on the rebased head is pending completion.

Checklist

• Read docs/CONTRIBUTING.md and docs/DEVELOPMENT.md.
• Commits are signed and follow conventional-commits style. (Conventional-commits style; unsigned.)

Related issues / PRs

Source-discovered Python bug, separate from the TypeScript filter feature in #838. This branch now includes the Python shutdown fix merged in #1142.