Copy operational notifications (Phase 2b)

Per-owner feed of safety-relevant copy events — destination tripping rejection breaker, account-protection hoặc prop-rule breach, panic flatten. On by default (App:Copy:NotificationsEnabled, default true); set false để silence. Own concept in Copy context, separate from market/AI AlertRule aggregate.

How it works

Same out-of-band host→sink→drainer pattern như execution-transparency log:

CopyEngineHost ──Notify(record)──▶ ICopyNotificationSink
                                     │
             (notifications off) NullCopyNotificationSink   → discards (no-op; unchanged engine)
             (notifications on)  ChannelCopyNotificationSink → bounded DropOldest channel
                                     │
                                     ▼
                            CopyNotificationDrainer (BackgroundService)
                                     │  resolves each profile's owner, batches
                                     ▼
                            CopyNotification feed  ◀── GET /api/copy/notifications

• Host Notify(...) non-blocking, never throws — không bao giờ touches DB, không bao giờ delays copy.
• Drainer resolves owning UserId từ each notification's profile; notification whose profile gone (owner unresolvable) dropped, not orphaned.
• CopyNotification = append-only, per-row-acknowledgeable feed (không phải aggregate).

What is raised

Kind	Severity	When
DestinationTripped	Warning	G8 rejection budget exhausted; new opens paused for the cooldown.
AccountProtectionTriggered	Critical	ZuluGuard equity floor/ceiling breached; opens latched (SellOut liquidates).
PropRuleBreached	Critical	Prop daily-loss / trailing-drawdown breached; destination flattened + locked out for the day.
FlattenAll	Critical	Panic flatten executed; every destination closed + locked.
TokenInvalidated	(reserved)	A destination's token was invalidated; awaiting rotation.

API

• GET /api/copy/notifications (owner-scoped) — user's recent notifications (most recent 200) across all profiles, cộng unacknowledged count.
• POST /api/copy/notifications/{id}/acknowledge — mark one read.

Configuration (App:Copy)

Setting	Default	Effect
NotificationsEnabled	true	Emit safety notifications + run the drainer. false → no-op sink.

Tests

• Unit (CopyNotificationTests) — tripped destination raises DestinationTripped; panic flatten raises profile-level FlattenAll. Via capturing sink.
• Integration (CopyNotificationDrainerTests, real Postgres) — drainer resolves owner + persists; notification for unknown profile dropped.
• DST — host emits fire-and-forget với no-op default sink, vì vậy copy stress suite stays green (23/23).