diff --git a/crates/ml-core/src/state_layout.rs b/crates/ml-core/src/state_layout.rs
index 693ace804..af37ad91d 100644
--- a/crates/ml-core/src/state_layout.rs
+++ b/crates/ml-core/src/state_layout.rs
@@ -53,3 +53,99 @@ const _: () = assert!(PADDING_START + PADDING_DIM == STATE_DIM, "layout must sum
 const _: () = assert!(STATE_DIM % 8 == 0, "STATE_DIM must be 8-aligned for tensor cores");
 const _: () = assert!(STATE_DIM_PADDED % 128 == 0, "STATE_DIM_PADDED must be 128-aligned for cuBLAS");
 const _: () = assert!(STATE_DIM <= STATE_DIM_PADDED, "STATE_DIM must fit within padded width");
+
+// ────────────────────────────────────────────────────────────────────────────
+// Mirrors of crates/ml/src/cuda_pipeline/state_layout.cuh PS_* constants.
+// Task 4A of Plan 1. Invariant 8.
+// ────────────────────────────────────────────────────────────────────────────
+
+pub const PS_POSITION:              usize = 0;  // current contract position (signed)
+pub const PS_CASH:                  usize = 1;  // cash balance
+pub const PS_PORTFOLIO_VALUE:       usize = 2;  // mark-to-market total (cash + pos*price)
+pub const PS_DSR_A:                 usize = 3;  // EMA of realised trade returns (DSR)
+pub const PS_DSR_B:                 usize = 4;  // EMA of squared trade returns (DSR)
+pub const PS_DSR_TRADE_COUNT:       usize = 5;  // completed trades counter (DSR warmup)
+pub const PS_PREV_CLOSE:            usize = 6;  // prev bar raw_close for DSR per-bar returns
+pub const PS_PEAK_EQUITY:           usize = 7;  // high-water mark (init to initial_capital)
+pub const PS_FLAT_COUNTER:          usize = 8;  // consecutive flat steps
+pub const PS_PREV_EQUITY:           usize = 9;  // equity at previous step
+pub const PS_HOLD_TIME:             usize = 10; // consecutive steps with position
+pub const PS_REALIZED_PNL:          usize = 11; // cumulative realised PnL
+pub const PS_ENTRY_PRICE:           usize = 12; // price when trade was entered
+pub const PS_TRADE_START_PNL:       usize = 13; // realized_pnl snapshot at trade entry
+pub const PS_KELLY_WIN_COUNT:       usize = 14; // Kelly: number of profitable trade exits
+pub const PS_KELLY_LOSS_COUNT:      usize = 15; // Kelly: number of losing trade exits
+pub const PS_KELLY_SUM_WINS:        usize = 16; // Kelly: cumulative profit from winners
+pub const PS_KELLY_SUM_LOSSES:      usize = 17; // Kelly: cumulative |loss| from losers
+pub const PS_KELLY_SUM_RETURNS:     usize = 18; // Kelly: cumulative net returns (for mu)
+pub const PS_KELLY_SUM_SQ_RETURNS:  usize = 19; // Kelly: cumulative squared returns (sigma^2)
+pub const PS_INTRA_TRADE_MAX_DD:    usize = 20; // worst unrealised drawdown during trade (v8)
+pub const PS_INTRA_TRADE_MAX_PNL:   usize = 21; // best unrealised P&L during trade (hindsight)
+pub const PS_PREV_MID:              usize = 22; // prev bar MBP-10 mid-price
+pub const PS_PLAN_TARGET_BARS:      usize = 23; // plan: max hold bars (>0.5 = plan active)
+pub const PS_PLAN_PROFIT_TARGET:    usize = 24; // plan: raw profit threshold
+pub const PS_PLAN_STOP_LOSS:        usize = 25; // plan: raw stop threshold
+pub const PS_PLAN_SCALE_AGGRESSION: usize = 26; // plan: position ramp speed
+pub const PS_PLAN_CONVICTION:       usize = 27; // plan: conviction at entry [0,1]
+pub const PS_PLAN_ASYMMETRY:        usize = 28; // plan: profit/stop asymmetry
+pub const PS_PLAN_ENTRY_REGIME:     usize = 29; // plan: regime_stability at entry
+pub const PS_OFI_PREV_BASE:         usize = 30; // first OFI prev-bar slot (stride 8: [30..37])
+pub const PS_STRIDE:                usize = 38; // total portfolio state stride (== PORTFOLIO_STRIDE)
+
+// ────────────────────────────────────────────────────────────────────────────
+// Mirrors of PLAN_ISV_* constants (plan_isv[0..PLAN_ISV_DIM=6)).
+// Task 4B of Plan 1. Invariant 8.
+// ────────────────────────────────────────────────────────────────────────────
+
+pub const PLAN_ISV_PROGRESS:         usize = 0; // hold_time / target_bars (clamped to 2.0)
+pub const PLAN_ISV_PNL_VS_TARGET:    usize = 1; // unrealized / (profit_target × equity)
+pub const PLAN_ISV_PNL_VS_STOP:      usize = 2; // -unrealized / (stop_loss × equity)
+pub const PLAN_ISV_ENTRY_CONVICTION: usize = 3; // conviction at trade entry [0, 1]
+pub const PLAN_ISV_CONVICTION_DRIFT: usize = 4; // current conviction − entry conviction
+pub const PLAN_ISV_REGIME_SHIFT:     usize = 5; // |isv[11] − entry_regime_stability|
+pub const PLAN_ISV_DIM:              usize = 6;
+
+// ────────────────────────────────────────────────────────────────────────────
+// Mirrors of PLAN_PARAM_* constants (plan_params[0..PLAN_PARAM_DIM=6)).
+// Task 4C of Plan 1. Invariant 8.
+// ────────────────────────────────────────────────────────────────────────────
+
+pub const PLAN_PARAM_TARGET_BARS:      usize = 0; // max hold bars
+pub const PLAN_PARAM_PROFIT_TARGET:    usize = 1; // raw profit threshold %
+pub const PLAN_PARAM_STOP_LOSS:        usize = 2; // raw stop loss threshold %
+pub const PLAN_PARAM_SCALE_AGGRESSION: usize = 3; // position ramp speed
+pub const PLAN_PARAM_CONVICTION:       usize = 4; // position size fraction [0, 1]
+pub const PLAN_PARAM_ASYMMETRY:        usize = 5; // profit/stop ratio
+pub const PLAN_PARAM_DIM:              usize = 6;
+
+// ────────────────────────────────────────────────────────────────────────────
+// Mirrors of BRANCH_* constants (4-branch factored action).
+// Task 4D of Plan 1. Invariant 8.
+// ────────────────────────────────────────────────────────────────────────────
+
+pub const BRANCH_DIR:   usize = 0; // direction branch (4 actions: Short/Hold/Long/Flat)
+pub const BRANCH_MAG:   usize = 1; // magnitude branch (3 actions: Quarter/Half/Full)
+pub const BRANCH_ORD:   usize = 2; // order-type branch (3 actions)
+pub const BRANCH_URG:   usize = 3; // urgency branch (3 actions)
+pub const NUM_BRANCHES: usize = 4;
+
+// ────────────────────────────────────────────────────────────────────────────
+// Mirrors of DIR_* constants (direction action sub-indices).
+// Task 4E of Plan 1. Invariant 8.
+// ────────────────────────────────────────────────────────────────────────────
+
+pub const DIR_SHORT:       usize = 0; // open/maintain short position
+pub const DIR_HOLD:        usize = 1; // keep current position (no-op)
+pub const DIR_LONG:        usize = 2; // open/maintain long position
+pub const DIR_FLAT:        usize = 3; // close all positions to zero
+pub const NUM_DIRECTIONS:  usize = 4;
+
+// ────────────────────────────────────────────────────────────────────────────
+// Mirrors of MAG_* constants (magnitude action sub-indices).
+// Task 4F of Plan 1. Invariant 8.
+// ────────────────────────────────────────────────────────────────────────────
+
+pub const MAG_QUARTER:    usize = 0; // 0.25× max_position
+pub const MAG_HALF:       usize = 1; // 0.50× max_position
+pub const MAG_FULL:       usize = 2; // 1.00× max_position
+pub const NUM_MAGNITUDES: usize = 3;
diff --git a/crates/ml/src/cuda_pipeline/experience_kernels.cu b/crates/ml/src/cuda_pipeline/experience_kernels.cu
index ce1975201..7beadba05 100644
--- a/crates/ml/src/cuda_pipeline/experience_kernels.cu
+++ b/crates/ml/src/cuda_pipeline/experience_kernels.cu
@@ -1145,11 +1145,11 @@ extern "C" __global__ void experience_action_select(
     /* Plan direction lock: during active plan, force current direction */
     if (portfolio_states != NULL) {
         int ps_base_plan = i * PORTFOLIO_STRIDE;
-        int has_plan_active = (portfolio_states[ps_base_plan + 23] > 0.5f);
+        int has_plan_active = (portfolio_states[ps_base_plan + PS_PLAN_TARGET_BARS] > 0.5f);
         if (has_plan_active) {
-            float cur_pos_plan = portfolio_states[ps_base_plan + 0];
-            if (cur_pos_plan > 0.001f) dir_idx = 2;       /* Long locked */
-            else if (cur_pos_plan < -0.001f) dir_idx = 0;  /* Short locked */
+            float cur_pos_plan = portfolio_states[ps_base_plan + PS_POSITION];
+            if (cur_pos_plan > 0.001f) dir_idx = DIR_LONG;
+            else if (cur_pos_plan < -0.001f) dir_idx = DIR_SHORT;
         }
     }
 
@@ -1191,7 +1191,7 @@ extern "C" __global__ void experience_action_select(
      * how confident the contrarian direction is — useful for position sizing
      * consistently with the action actually being taken. */
     if (out_q_gaps != NULL) {
-        int flat_idx = 3; /* Flat = index 3 for direction(4): Short(0)/Hold(1)/Long(2)/Flat(3) */
+        int flat_idx = DIR_FLAT; /* Flat direction's Q-value index within the 4-way direction branch */
         float q_sign_local = (contrarian_active != 0) ? -1.0f : 1.0f;
         /* Find best action under the (possibly negated) Q. */
         int best_idx = 0;
diff --git a/docs/dqn-named-dims.md b/docs/dqn-named-dims.md
index c0ca84345..d7ac9ae4a 100644
--- a/docs/dqn-named-dims.md
+++ b/docs/dqn-named-dims.md
@@ -124,3 +124,7 @@ From the trade_plan MLP output.
 - Task 4D (BRANCH_* constants): commit 11755632b
 - Task 4E (DIR_* direction sub-indices): commit c64fde0be
 - Task 4F (MAG_* magnitude sub-indices): commit 537e18b84
+- Task 4 gap-fix (3 review issues): experience_kernels.cu lines 1148-1152 and 1194 missed by
+  sed sweep (ps_base_plan+N syntax), replaced with PS_PLAN_TARGET_BARS/PS_POSITION/DIR_LONG/
+  DIR_SHORT/DIR_FLAT; ml-core state_layout.rs Rust mirror added for all Task 4 constants
+  (PS_*/PLAN_ISV_*/PLAN_PARAM_*/BRANCH_*/DIR_*/MAG_*, 46 constants total).