fix(analytics): remove duplicate sessionId index definition

- SessionSchema had both 'unique: true' and 'index: true'
- unique already creates an index, making index redundant
- Resolves Mongoose warning about duplicate schema index

.claude/session-state.json

@@ -43,8 +43,8 @@
       "last_deliberation": null
     },
     "FileEditHook": {
-      "timestamp": "2025-10-23T21:07:21.094Z",
-      "file": "/home/theflow/projects/tractatus/src/models/SubmissionTracking.model.js",
+      "timestamp": "2025-10-23T21:21:14.842Z",
+      "file": "/home/theflow/projects/tractatus/src/models/Analytics.model.js",
       "result": "passed"
     },
     "FileWriteHook": {
@@ -58,25 +58,25 @@
     "tokens": 30000
   },
   "alerts": [],
-  "last_updated": "2025-10-23T21:07:21.094Z",
+  "last_updated": "2025-10-23T21:21:14.842Z",
   "initialized": true,
   "framework_components": {
     "CrossReferenceValidator": {
       "message": 0,
       "tokens": 0,
-      "timestamp": "2025-10-23T21:19:30.192Z",
-      "last_validation": "2025-10-23T21:19:30.191Z",
-      "validations_performed": 676
+      "timestamp": "2025-10-23T21:21:26.151Z",
+      "last_validation": "2025-10-23T21:21:26.150Z",
+      "validations_performed": 679
     },
     "BashCommandValidator": {
       "message": 0,
       "tokens": 0,
       "timestamp": null,
-      "last_validation": "2025-10-23T21:19:30.193Z",
-      "validations_performed": 335,
+      "last_validation": "2025-10-23T21:21:26.152Z",
+      "validations_performed": 337,
       "blocks_issued": 37
     }
   },
-  "action_count": 335,
+  "action_count": 337,
   "auto_compact_events": []
 }

src/models/Analytics.model.js

@@ -46,7 +46,7 @@ PageViewSchema.index({ sessionId: 1, timestamp: -1 });
 
 // Session Schema
 const SessionSchema = new mongoose.Schema({
-  sessionId: { type: String, required: true, unique: true, index: true },
+  sessionId: { type: String, required: true, unique: true }, // unique already creates index
   visitorId: { type: String, required: true, index: true },
 
   startTime: { type: Date, default: Date.now },