Remove top-level v1/v2 after moving to legacy/

v2/source/source_metadata.json

@@ -1,18 +0,0 @@
-{
-  "version": "v2_source_metadata_v1",
-  "files": [
-    {
-      "path": "v2/v2_behavior_features_merged_pospnl_kline_v2_fixcost.parquet",
-      "alias": "behavior_fixcost.parquet"
-    },
-    {
-      "path": "v2/v2_trade_price_matched_pre80m_cap30.parquet",
-      "alias": "trade_price_matched.parquet"
-    },
-    {
-      "path": "v2/v2_market_semantic_from_behavior_cap30_pricecovered.parquet",
-      "alias": "market_semantic.parquet"
-    }
-  ],
-  "note": "Source parquet files already exist under v2/ root in this repo."
-}