chore: Second cleanup wave - organize root directory

- Archive: 85 agent .txt files → docs/archive/agents/legacy_txt/
- Scripts: Move 110 shell scripts → scripts/ (keep deploy.sh in root)
- Models: Move 18 .safetensors → ml/models/checkpoints/training_artifacts/
- Delete: 34 directories (~33GB freed) - target/, coverage_*, test artifacts
- Build: Clean 14 build artifacts (.rlib, .o, .pid, binaries)
- Tests: Move 14 .rs files → tests/standalone/
- SQL: Move 5 files → sql/ (keep init-db*.sql for Docker)
- Wave 153: Archive to docs/archive/historical/wave153/
- Docs: Archive 9 markdown files to wave_d/reports/ and historical/

Total impact: ~34GB freed (both waves), root directory cleaned from 583 to ~40 essential files
Directory count reduced from 65 to 31 (52% reduction)
All historical data preserved in organized archive structure

sql/trading_workload.sql

@@ -0,0 +1,59 @@
+-- Trading workload SQL for pgbench
+-- 40% INSERT, 30% SELECT, 20% UPDATE, 10% Complex queries
+
+\set account_id 'test_account_' :client_id
+\set venue 'test_venue'
+\set symbol random(1, 3)
+
+-- Map random number to symbol
+\if :symbol = 1
+    \set symbol_str 'BTC/USD'
+\elif :symbol = 2
+    \set symbol_str 'ETH/USD'
+\else
+    \set symbol_str 'SOL/USD'
+\endif
+
+\set operation random(1, 10)
+
+-- 40% INSERT (operations 1-4)
+\if :operation <= 4
+INSERT INTO orders (account_id, symbol, side, order_type, quantity, limit_price, venue, created_at, updated_at)
+VALUES (:'account_id', :'symbol_str', 'buy', 'limit', 100000000, 5000000000000, :'venue',
+        EXTRACT(EPOCH FROM NOW()) * 1000000000, EXTRACT(EPOCH FROM NOW()) * 1000000000);
+
+-- 30% SELECT (operations 5-7)
+\elif :operation <= 7
+SELECT id, status, quantity, filled_quantity
+FROM orders
+WHERE symbol = :'symbol_str'
+ORDER BY created_at DESC
+LIMIT 10;
+
+-- 20% UPDATE (operations 8-9)
+\elif :operation <= 9
+UPDATE orders
+SET status = 'partially_filled',
+    filled_quantity = filled_quantity + 10000000,
+    updated_at = EXTRACT(EPOCH FROM NOW()) * 1000000000
+WHERE id = (
+    SELECT id
+    FROM orders
+    WHERE status = 'pending'
+    AND symbol = :'symbol_str'
+    LIMIT 1
+);
+
+-- 10% Complex query (operation 10)
+\else
+SELECT symbol,
+       COUNT(*) as order_count,
+       SUM(quantity) as total_quantity,
+       AVG(limit_price) as avg_price,
+       COUNT(DISTINCT account_id) as unique_accounts
+FROM orders
+WHERE created_at > EXTRACT(EPOCH FROM (NOW() - INTERVAL '1 hour')) * 1000000000
+GROUP BY symbol
+ORDER BY order_count DESC;
+
+\endif