Only log suspicious-sweep actions, not routine no-op skips/clears

With the sweep now running every 10 minutes, the per-run 'N due' summary
and per-account skip/clear log lines (already-limited, staff, cleared by
activity, not found) were mostly noise drowning out the actual suspend/
silence actions. Those states are still recorded in suspicious_watch.status
for anyone querying the DB directly; only the taken action, dry-run
simulation, and error paths still log.

app/suspicious_sweep.py

@@ -97,11 +97,9 @@ def _is_allowlisted(acct: str) -> bool:
 
 def sweep() -> None:
     if not SUSPICIOUS_SWEEP_ENABLED:
-        log.info("SUSPICIOUS_SWEEP_ENABLED=false, nothing to do")
         return
 
     due = _pending_due()
-    log.info("%d flagged signup(s) past the %dh grace window", len(due), SUSPICIOUS_GRACE_HOURS)
 
     for account_id, acct, reasons, baseline_statuses, baseline_following in due:
         try:
@@ -111,17 +109,14 @@ def sweep() -> None:
             continue
 
         if admin_acct is None:
-            log.info("acct=%s no longer exists, clearing watch", acct)
             _resolve(account_id, "skipped-not-found")
             continue
 
         if admin_acct.get("suspended") or admin_acct.get("silenced"):
-            log.info("acct=%s already limited by another mechanism, clearing watch", acct)
             _resolve(account_id, "skipped-already-limited")
             continue
 
         if (_is_privileged(admin_acct) and ABUSE_SKIP_PRIVILEGED) or _is_allowlisted(acct):
-            log.info("acct=%s is staff/allowlisted, clearing watch", acct)
             _resolve(account_id, "skipped-privileged")
             continue
 
@@ -130,10 +125,6 @@ def sweep() -> None:
         following_count = public.get("following_count", 0)
 
         if statuses_count > baseline_statuses or following_count > baseline_following:
-            log.info(
-                "acct=%s showed activity since flagging (posts %d->%d, following %d->%d), clearing watch",
-                acct, baseline_statuses, statuses_count, baseline_following, following_count,
-            )
             _resolve(account_id, "cleared")
             continue