feat(monitoring): generate daily tasks and optimize heartbeat writes

Adds a MonitoringDailyTaskWorker that materializes and dispatches
daily collect tasks from active subscription/desktop-client state,
with per-run atomic metrics and a Prometheus collector. Dashboard
and question-detail APIs now surface a platform_authorization_status
so the UI can distinguish no-desktop-client, no-authorized-platforms,
and authorized states; quota/access-state lookups resolve by request
workspace instead of tenant.

Hardens heartbeat: a desktop_client_primary_leases table gives
per-(tenant, workspace) sticky primary selection, read-mostly lease
resolution avoids a per-heartbeat transaction, and unchanged platform
access reports skip snapshot upserts outside a 10-minute refresh
window. Adds heartbeat primary/snapshot metrics exposed via
token-protected tenant-api /api/internal/metrics endpoints plus
Prometheus. Monitoring quota seed is removed from dev-seed since
daily plans now derive from desktop bindings, and the projection
uses the canonical six-platform catalog so platforms with zero
samples still render.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/internal/tenant/app/desktop_presence.go

@@ -9,6 +9,9 @@ import (
 	goredis "github.com/redis/go-redis/v9"
 )
 
+// desktopClientPresenceTTL is also used as the monitoring primary-client lease TTL.
+// Desktop heartbeat interval must stay below TTL/2, so one missed heartbeat does
+// not make another client eligible to steal a still-healthy primary lease.
 const desktopClientPresenceTTL = 90 * time.Second
 const desktopAccountPresenceTTL = 90 * time.Second