feat(insights): choose the status regeneration gap by ingest source

A sync from a watch or an integration now waits the instance's sync gap
(AppSettings.aiSyncRegenGapHours, else AI_SYNC_REGEN_GAP_HOURS, else 6 h)
before it may regenerate a status card again; a hand entry keeps the hour.
Every caller of afterMeasurementMutation and invalidateStatusInsightsForTypes
names its source, so a new ingest path cannot skip the choice.

Refs #1217

scripts/env-manifest.json

@@ -142,6 +142,10 @@
           "name": "DOCUMENT_AI_LIMIT_PER_HOUR",
           "purpose": "Per-user hourly ceiling for the document-AI actions (read/index, extract, suggest, summarise share one bucket). Default 6, clamped to 1-1000."
         },
+        {
+          "name": "AI_SYNC_REGEN_GAP_HOURS",
+          "purpose": "Minimum hours between two status-card regenerations after a sync. Default 6, whole hours 1-48; hand entries keep one hour. The admin AI setting wins."
+        },
         {
           "name": "DOCUMENT_UPLOAD_LIMIT_PER_HOUR",
           "purpose": "Hourly upload ceiling per document-upload token (Paperless workflow, import script). Default 120, clamped to 1-1000. Web and phone uploads keep their own bucket."