feat(notifications): deep-link bell rows to source stack and container logs (#692)

Add stack_name and container_name columns to notification_history so bell
rows can act as jump points. Producers (AutoHeal, Docker events) pass the
container context through dispatchAlert; the panel renders routable rows
as buttons that load the target stack and, when a container name is
present, open its logs modal. Non-structural notifications stay as
passive display rows.

backend/src/services/AutoHealService.ts

@@ -244,6 +244,7 @@ export class AutoHealService {
                     'info',
                     `Auto-Heal: Restarted ${containerName} on stack ${policy.stack_name} after being unhealthy for ${policy.unhealthy_duration_mins} minute(s).`,
                     policy.stack_name,
+                    containerName,
                 )
                 .catch(err => console.error('[AutoHeal] notification dispatch failed:', err));
         } catch (err) {
@@ -267,6 +268,7 @@ export class AutoHealService {
                     'warning',
                     `Auto-Heal: Failed to restart ${containerName} on stack ${policy.stack_name}. Error: ${errorMsg}`,
                     policy.stack_name,
+                    containerName,
                 )
                 .catch(e => console.error('[AutoHeal] notification dispatch failed:', e));