Allow proactivity despite stale bootstrap flags

[inchwormz]

Summary\n- Fixes proactivity deferring when a strategy scope has stale bootstrap flags but real interrupt-level nudges.\n- Adds a regression test for the stale-bootstrap-with-nudges path.\n- Bumps crate version to 0.5.3.\n\n## Root cause\nThe local strategy registry can retain \�ootstrap_requested = true\ / \ emplate_managed = true\ even after a real strategy artifact is imported. Proactivity treated that stale flag as a hard defer before considering real nudges.\n\n## Verification\n- \cargo test --quiet\n- \cargo test --quiet --lib core::proactivity\n- \cargo publish --dry-run\n- Manual reproduction: \munin proactivity run --scope sitesorted-business --no-spawn --format json\ now returns \queue-approval\ instead of \deferred/bootstrap_strategy_scope.\n