v1.1.1fossic2026-06-20

SystemStreamWriter — dedicated system-stream connection

Extracts write_degraded_event into SystemStreamWriter; dispatcher thread holds one dedicated SQLite connection outside the write mutex. Byte-identical SubscriptionDegraded output. Phase 1 anchor comments added for Track 2 merge safety.

v1.1.12026-06-20

·SystemStreamWriter owns its connection outside the write mutex and read pool — system events never contend with user appends
·emit() derives the CCE event id internally; call sites never handle ids
·emit_subscription_degraded preserves byte-identical payload field order and CCE id — all 246 tests pass unchanged