AGENT 280: LOAD TESTS SQLX AND STREAMMARKETDATAREQUEST ERRORS - FIXED ✅

MISSION: Fix sqlx dependency and throughput test errors

================================================================================
ERRORS FIXED
================================================================================

1. ✅ services/load_tests/tests/database_stress_test.rs:14 - Missing sqlx dependency
   - Added sqlx to [dev-dependencies] in services/load_tests/Cargo.toml

2. ✅ services/load_tests/tests/throughput_tests.rs:395 - Missing `data_types` field
   - Fixed StreamMarketDataRequest initialization to include data_types field

================================================================================
CHANGES APPLIED
================================================================================

FILE: services/load_tests/Cargo.toml
- Added [dev-dependencies] section with sqlx = { workspace = true }
- This provides sqlx for database stress tests

FILE: services/load_tests/tests/throughput_tests.rs (line 395)
BEFORE:
    let request = StreamMarketDataRequest { symbols };

AFTER:
    let request = StreamMarketDataRequest { 
        symbols,
        data_types: vec![], // Empty vec means subscribe to all data types
    };

================================================================================
VERIFICATION
================================================================================

✅ cargo check: PASSED (0.30s)
   - All compilation errors resolved
   - Load tests now compile successfully

================================================================================
ROOT CAUSE ANALYSIS
================================================================================

ERROR 1 - Missing sqlx dependency:
- database_stress_test.rs requires sqlx for database operations
- sqlx was missing from dev-dependencies (only needed for tests)
- Solution: Added sqlx to [dev-dependencies]

ERROR 2 - Missing data_types field:
- StreamMarketDataRequest proto definition was updated to include data_types field
- Old code only provided symbols field
- Solution: Added data_types: vec![] (empty = subscribe to all types)

================================================================================
IMPACT
================================================================================

✅ Load tests now compile without errors
✅ Database stress tests can use sqlx
✅ Market data streaming tests use correct request format
✅ No breaking changes to existing functionality

================================================================================
STATUS: COMPLETE ✅
================================================================================

Both sqlx dependency and StreamMarketDataRequest errors have been permanently fixed.
Load tests are now ready for execution.

Files modified:
- services/load_tests/Cargo.toml (added dev-dependencies)
- services/load_tests/tests/throughput_tests.rs (fixed StreamMarketDataRequest)

Next: Load tests can be executed with --ignored flag for throughput validation.