Add deduplication clarification comments for Ceph ticket handling

Explains that the ticket API deduplicates using SHA-256 hash of
(category + tags + hostname + device), not description/timestamp.
Clarifies the 24-hour dedup window and cluster-wide hostname exclusion.

Fixes: #18

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hwmonDaemon.py

@@ -1772,6 +1772,10 @@ class SystemHealthMonitor:
             )
             description = self._generate_detailed_description(issue, health_report, priority)
 
+            # NOTE: The ticket API (create_ticket_api.php) deduplicates using a SHA-256 hash of:
+            #   issue_category + environment_tags + hostname (excluded for [cluster-wide]) + device
+            # Description content and timestamps are NOT included in the dedup hash.
+            # The 24-hour dedup window prevents duplicate tickets from multiple nodes or runs.
             ticket_payload = {
                 "title": ticket_title,
                 "description": description,
@@ -1895,7 +1899,8 @@ class SystemHealthMonitor:
             designated_node = self.CONFIG.get('CEPH_TICKET_NODE')
 
             # Cluster-wide issues: only create tickets from designated node (or first node if not set)
-            # The [cluster-wide] tag ensures deduplication in tinker_tickets API
+            # The [cluster-wide] tag + CLUSTER_NAME in ticket title ensures cross-node deduplication
+            # in the tinker_tickets API (dedup hash excludes hostname for cluster-wide issues)
             if ceph_health.get('cluster_wide_issues'):
                 # If no designated node, all nodes can report (API deduplicates)
                 # If designated node is set, only that node creates tickets
@@ -2999,7 +3004,7 @@ class SystemHealthMonitor:
             'osd_status': [],
             'mon_status': [],
             'issues': [],
-            'cluster_wide_issues': []  # Issues that apply to entire cluster
+            'cluster_wide_issues': []  # Issues affecting entire cluster; use CLUSTER_NAME for dedup
         }
 
         # Check if Ceph monitoring is enabled