Update README.md with recent forum synchronization details and historical baseline information

- Revised the initial organization date and added recent synchronization date for clarity.
- Included details on the number of posts and comments indexed as of September 11, 2026, along with updates on newly added content.
- Clarified the status of historical baseline data and the process of filtering and reviewing forum posts and comments.

docs/worldquant-knowledge-base/06-sources/collection-2026.json

@@ -27,5 +27,55 @@
     "Not every comment or embedded image was deeply reviewed.",
     "Community performance claims were not backtested.",
     "No source authentication material is included."
-  ]
+  ],
+  "latest_forum_sync": {
+    "collected_at": "2026-09-11",
+    "timezone": "Asia/Shanghai",
+    "started_at": "2026-09-11T01:03:40.336597+00:00",
+    "collection_finished_at": "2026-09-11T01:06:33.369594+00:00",
+    "raw_visible_posts": 1730,
+    "raw_list_pages": 18,
+    "excluded_older_posts": 1101,
+    "retained_posts": 629,
+    "retained_comments": 9587,
+    "newly_indexed_posts": 6,
+    "newly_indexed_posts_created_sep_7_or_later": 5,
+    "previously_unindexed_sep_5_posts": 1,
+    "comments_on_newly_indexed_posts": 9,
+    "historical_comments_backfilled_on_existing_posts": 6,
+    "comment_count_net_change": 15,
+    "metadata_changed_existing_posts": 141,
+    "body_edit_count": null,
+    "comment_edit_count": null,
+    "failed_comment_records": 0,
+    "missing_previously_indexed_posts": 0,
+    "posts_cited_in_knowledge": 122,
+    "groups": {
+      "engineering": 69,
+      "guides": 7,
+      "events": 39,
+      "general": 96,
+      "ai": 143,
+      "portfolio": 48,
+      "ideas": 19,
+      "lessons": 128,
+      "optimization": 61,
+      "data": 19
+    },
+    "recent_comment_records_screened": 244,
+    "recent_comment_posts_screened": 87,
+    "official_articles_checked": [
+      "43302575764631",
+      "43302563775127",
+      "43302607437719",
+      "43302607372183"
+    ],
+    "baseline_state_directory": ".local/forum-sync/",
+    "limits": [
+      "First content-fingerprint baseline; metadata changes do not establish body edits.",
+      "Historical zero-comment records corrected for three existing posts; net count change is not newly published comments.",
+      "All scoped comments fetched, selective historical body reading; images and attachments not fully verified.",
+      "No simulations, submissions, email sync, public publishing, or credential/session persistence."
+    ]
+  }
 }