fix(crt-1): add delta_floor: 0.0 to 3 missing test UniformSimParams initializers

The C1.3 commit 7c850a6c0 missed three test files that construct
UniformSimParams literals. cargo check reported E0063 missing-field
errors. Added delta_floor: 0.0 (band disabled, preserves pre-C1.3
behavior in tests) to:
  - parallel_sim_correctness.rs
  - decision_floor_coldstart.rs
  - lob_sim_integrated_fuzz.rs

Per feedback_no_partial_refactor: the atomic refactor must include
every consumer in one logical change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/ml-backtesting/tests/decision_floor_coldstart.rs

@@ -44,6 +44,7 @@ fn cfg_uniform(n: usize, kelly: f32, sharpe: f32) -> BatchedSimConfig {
         // weight denominator. 1.0 is a typical futures round-trip cost.
         cost_per_lot_per_side:   1.0,
         max_hold_ns:             0,
+        delta_floor:             0.0,
         min_reasonable_px:       0.0,
         max_reasonable_px:       f32::INFINITY,
     })

crates/ml-backtesting/tests/lob_sim_integrated_fuzz.rs

@@ -132,6 +132,7 @@ fn run_integrated_fuzz(n_backtests: usize, n_events: usize, seed: u64) -> Result
                     threshold:               0.0,
                     cost_per_lot_per_side:   0.0,
                     max_hold_ns:             0,
+                    delta_floor:             0.0,
                     min_reasonable_px:       0.0,
                     max_reasonable_px:       f32::INFINITY,
                 },

crates/ml-backtesting/tests/parallel_sim_correctness.rs

@@ -38,6 +38,7 @@ fn parallel_sim_equivalence_with_uniform_config() -> Result<()> {
             // round-trip cost.
             cost_per_lot_per_side:   1.0,
             max_hold_ns:             0,
+            delta_floor:             0.0,
             min_reasonable_px:       0.0,
             max_reasonable_px:       f32::INFINITY,
         },