Allow infra to listen to activity actively

backend/spec/command.md

@@ -5,15 +5,19 @@ Command writes to the database.
 Members:
 
 - `pool: SqlitePool` - a sqlite connection pool
+- `pub notify: broadcast::Sender<Activity>` - callers can subscribe via `command.notify.subscribe()`
 
 Notes:
 
 - All public write methods should be atomic
 - All writes should be accompanied by an activity log entry of `(tenant, activity_type, resource_type, resource_id)`
+- `insert_activity` builds and returns the `Activity` struct (using `chrono::Utc::now()` for `created_at`)
+- After each successful commit, sends the `Activity` on the broadcast channel
 
 ## `pub fn new(&self, pool: SqlitePool) -> Self`
 
 - Assigns pool to self
+- Creates the broadcast channel
 
 ## `pub fn create_tenant(&self, tenant: &Tenant) -> Result<()>`
 
@@ -51,7 +55,7 @@ Notes:
 - Sets relay status to `inactive`, sets `sync_error`
 - Logs activity as `(fail_relay_sync, relay_id)`
 
-## `pub fn mark_relay_synced(&self, relay_id: &str) -> Result<()>`
+## `pub fn complete_relay_sync(&self, relay_id: &str) -> Result<()>`
 
 - Sets `synced = 1`, `status = 'active'`, clears `sync_error`
-- No activity log (called by infra after successful sync)
+- Logs activity as `(complete_relay_sync, relay_id)`