feat(automation): add timezone-safe daily briefing dedupe

README.md

@@ -532,6 +532,7 @@ automation:
         peer: "123456789"               # Chat ID to send to
       timezone: Europe/London           # Optional timezone
       enabled: true
+      once_per_local_day: false         # Optional dedupe: max one trigger/day in job timezone
 
     - name: hourly-check
       schedule: "0 * * * *"            # Every hour
@@ -549,6 +550,7 @@ automation:
     name: daily-briefing
     schedule: "0 8 * * *"
     timezone: America/New_York
+    dedupe_per_local_day: true
     output:
       channel: telegram
       peer: "123456789"
@@ -571,6 +573,7 @@ automation:
 | `timezone` | no | IANA timezone (defaults to system timezone) |
 | `enabled` | no | Whether the job is active (default: `true`) |
 | `model_tier` | no | Model tier for this job: `fast`, `default`, `complex`, or `local` |
+| `once_per_local_day` | no | If true, suppress duplicate triggers within the same local day (job timezone) |
 | `automation.daily_briefing.*` | no | Built-in daily briefing preset; generates an extra cron job when `enabled: true` and `output` is set |
 
 ## Backup Scheduling