revert: drop exit-gate configurability, hardcode the replay-validated values

Operator call: no per-strategy configurability for exit pacing — it added
config fields, UI and plumbing nobody wanted. Back to plain constants in
auto_trader_throttle.go, now set to the replay-validated values instead
of the original guesses (4154 cycles, 3-fold robust search over only the
7 exit params, everything else fixed at the live config):

- min hold 90m, noise-close window 3h, noise band -2%..+3%,
  bypasses -3%/+8% (all inside the searched top-20 ranges)
- re-entry cooldown 4h — the one clear signal: top-20 configs cluster
  tightly at 3.8-4.0h; re-entering a just-closed symbol was a consistent
  loss source

Removes the 7 RiskControlConfig fields + accessors, the Strategy Studio
'exit pacing' row, the frontend type fields, and the fields from stored
strategy configs in data/data.db. Prompt guidance is static text again,
matching the constants.

web/src/pages/StrategyStudioPage.tsx

@@ -2321,68 +2321,6 @@ export function StrategyStudioPage() {
                         </select>
                       </label>
                     </div>
-                    <div className="mt-4 grid gap-4 sm:grid-cols-3">
-                      <label className="space-y-2">
-                        <span className="text-xs text-nofx-text-muted">
-                          {text(language, '最小持仓时间', 'Min hold')}
-                        </span>
-                        <select
-                          value={risk.min_hold_minutes ?? 90}
-                          onChange={(event) =>
-                            patchRisk({
-                              min_hold_minutes: Number(event.target.value),
-                            })
-                          }
-                          className="w-full rounded-lg border border-[rgba(26,24,19,0.14)] bg-nofx-bg px-3 py-2 text-sm text-nofx-text"
-                        >
-                          {[30, 60, 90, 120, 180, 240].map((value) => (
-                            <option key={value} value={value}>
-                              {value >= 60 ? `${value / 60}h` : `${value}m`}
-                            </option>
-                          ))}
-                        </select>
-                      </label>
-                      <label className="space-y-2">
-                        <span className="text-xs text-nofx-text-muted">
-                          {text(language, '横盘仓锁定窗口', 'Flat-close window')}
-                        </span>
-                        <select
-                          value={risk.noise_hold_minutes ?? 180}
-                          onChange={(event) =>
-                            patchRisk({
-                              noise_hold_minutes: Number(event.target.value),
-                            })
-                          }
-                          className="w-full rounded-lg border border-[rgba(26,24,19,0.14)] bg-nofx-bg px-3 py-2 text-sm text-nofx-text"
-                        >
-                          {[60, 120, 180, 240, 360, 480].map((value) => (
-                            <option key={value} value={value}>
-                              {`${value / 60}h`}
-                            </option>
-                          ))}
-                        </select>
-                      </label>
-                      <label className="space-y-2">
-                        <span className="text-xs text-nofx-text-muted">
-                          {text(language, '同币再入冷却', 'Re-entry cooldown')}
-                        </span>
-                        <select
-                          value={risk.reentry_cooldown_minutes ?? 90}
-                          onChange={(event) =>
-                            patchRisk({
-                              reentry_cooldown_minutes: Number(event.target.value),
-                            })
-                          }
-                          className="w-full rounded-lg border border-[rgba(26,24,19,0.14)] bg-nofx-bg px-3 py-2 text-sm text-nofx-text"
-                        >
-                          {[30, 60, 90, 120, 180].map((value) => (
-                            <option key={value} value={value}>
-                              {value >= 60 ? `${value / 60}h` : `${value}m`}
-                            </option>
-                          ))}
-                        </select>
-                      </label>
-                    </div>
                   </div>
                 </div>
 

web/src/types/strategy.ts

@@ -209,14 +209,4 @@ export interface RiskControlConfig {
   min_position_size: number;       // Min position size in USDT (CODE ENFORCED)
   min_risk_reward_ratio: number;   // Min take_profit / stop_loss ratio (AI guided)
   min_confidence: number;          // Min AI confidence to open position (AI guided)
-
-  // Exit throttle gates (CODE ENFORCED, 0/absent = backend defaults).
-  // PnL thresholds are PRICE-move percentages (leverage-independent).
-  min_hold_minutes?: number;        // AI closes blocked before this unless a bypass fires
-  noise_hold_minutes?: number;      // flat closes inside the noise band blocked until this
-  reentry_cooldown_minutes?: number; // same-symbol reopen cooldown after a close
-  early_stop_bypass_pct?: number;   // price loss unlocking an early close (negative)
-  early_tp_bypass_pct?: number;     // price profit unlocking an early close (positive)
-  noise_loss_floor_pct?: number;    // noise band lower edge (negative)
-  noise_profit_ceiling_pct?: number; // noise band upper edge (positive)
 }