Add reserve pressure user input to dive planner (#67)

* UI tests for editable reserve pressure field (TDD red)

* Implement requirements for UX of user input of reserve pressure in dive planning

* Add tests for plan calculator to ensure that user entry of reserve is respected in the calculations

* Update dive planner to respect reserve pressure entered by user (TDD green phase)

* dart format . corrections

* fix: use ref.read for pressureUnitProvider to prevent plan state reset

ref.watch inside divePlanNotifierProvider caused the entire notifier to be
recreated when the user changed their pressure unit in settings, destroying
all in-progress plan segments, tanks, and edits.

Changed to ref.read since the pressure unit is only needed to compute the
initial default reserve pressure value, not to reactively track changes.

Fixes CODE_REVIEW.md issue #1 (HIGH).

* feat: validate reserve pressure input with localized errors

* fix: wrap reserve pressure input in Expanded to prevent row overflow on narrow screens

* feat: reset to default reserve pressure when field cleared, with localized info message

* fix: add Semantics label to reserve pressure TextField for screen readers

* fix: display exact user-entered reserve pressure in warning messages

* refactor: extract magic number 50 to DivePlanState.kDefaultReservePressureBar constant

* style: dart format corrections

* fix: use max tank pressure instead of sum for reserve validation to match calculator logic

* Add pull request description for editable reserve pressure feature

* fix: enforce digits-only input on reserve pressure field

* Remove PUSH_TEMPLATE.md

* Add tests for missing coverage flagged by codecov bot

Author: essengee

lib/features/dive_planner/data/services/plan_calculator_service.dart

@@ -55,11 +55,13 @@ class PlanCalculatorService {
   /// [segments] - The dive plan segments in order.
   /// [tanks] - Available tanks with starting pressures and volumes.
   /// [sacRate] - Surface Air Consumption in L/min.
+  /// [reservePressure] - Reserve pressure threshold in bar.
   /// [initialTissueState] - Tissue state from previous dive (for repetitive).
   PlanResult calculatePlan({
     required List<PlanSegment> segments,
     required List<DiveTank> tanks,
     required double sacRate,
+    double reservePressure = DivePlanState.kDefaultReservePressureBar,
     List<TissueCompartment>? initialTissueState,
   }) {
     if (segments.isEmpty) {
@@ -301,15 +303,16 @@ class PlanCalculatorService {
               value: remainingPressure.toDouble(),
             ),
           );
-        } else if (remainingPressure != null && remainingPressure < 50) {
+        } else if (remainingPressure != null &&
+            remainingPressure < reservePressure) {
           warnings.add(
             PlanWarning(
               type: PlanWarningType.gasLow,
               severity: PlanWarningSeverity.alert,
               message:
-                  'Tank ${tank.name ?? tank.gasMix.name} below 50 bar reserve',
+                  'Tank ${tank.name ?? tank.gasMix.name} below ${reservePressure.toStringAsFixed(0)} bar reserve',
               value: remainingPressure.toDouble(),
-              threshold: 50,
+              threshold: reservePressure,
             ),
           );
         }
@@ -325,7 +328,8 @@ class PlanCalculatorService {
             remainingPressure: remainingPressure,
             percentUsed: percentUsed,
             reserveViolation:
-                remainingPressure != null && remainingPressure < 50,
+                remainingPressure != null &&
+                remainingPressure < reservePressure,
           ),
         );
       }

lib/features/dive_planner/domain/entities/plan_result.dart

@@ -461,6 +461,9 @@ class PlanResult extends Equatable {
 
 /// State of a dive plan being edited.
 class DivePlanState extends Equatable {
+  /// Default reserve pressure in bar.
+  static const double kDefaultReservePressureBar = 50;
+
   /// Unique ID for this plan.
   final String id;
 
@@ -494,6 +497,9 @@ class DivePlanState extends Equatable {
   /// Altitude above sea level in meters (for altitude diving).
   final double? altitude;
 
+  /// Reserve pressure in bar.
+  final double reservePressure;
+
   /// Notes for the plan.
   final String notes;
 
@@ -518,6 +524,7 @@ class DivePlanState extends Equatable {
     this.initialTissueState,
     this.siteId,
     this.altitude,
+    this.reservePressure = kDefaultReservePressureBar,
     this.notes = '',
     this.isDirty = false,
     required this.createdAt,
@@ -564,6 +571,7 @@ class DivePlanState extends Equatable {
     List<TissueCompartment>? initialTissueState,
     String? siteId,
     double? altitude,
+    double? reservePressure,
     String? notes,
     bool? isDirty,
     DateTime? createdAt,
@@ -589,6 +597,7 @@ class DivePlanState extends Equatable {
           : (initialTissueState ?? this.initialTissueState),
       siteId: clearSiteId ? null : (siteId ?? this.siteId),
       altitude: clearAltitude ? null : (altitude ?? this.altitude),
+      reservePressure: reservePressure ?? this.reservePressure,
       notes: notes ?? this.notes,
       isDirty: isDirty ?? this.isDirty,
       createdAt: createdAt ?? this.createdAt,
@@ -609,6 +618,7 @@ class DivePlanState extends Equatable {
     initialTissueState,
     siteId,
     altitude,
+    reservePressure,
     notes,
     isDirty,
     createdAt,

lib/features/dive_planner/presentation/providers/dive_planner_providers.dart

@@ -1,6 +1,7 @@
 import 'package:uuid/uuid.dart';
 
 import 'package:submersion/core/constants/enums.dart';
+import 'package:submersion/core/constants/units.dart';
 import 'package:submersion/core/providers/provider.dart';
 import 'package:submersion/features/dive_log/domain/entities/dive.dart';
 import 'package:submersion/features/settings/presentation/providers/settings_providers.dart';
@@ -38,16 +39,24 @@ final planCalculatorServiceProvider = Provider<PlanCalculatorService>((ref) {
 /// StateNotifier for managing dive plan editing state.
 class DivePlanNotifier extends StateNotifier<DivePlanState> {
   final PlanCalculatorService _calculator;
+  final double _defaultReservePressure;
 
-  DivePlanNotifier(this._calculator) : super(_createInitialState());
+  DivePlanNotifier(
+    this._calculator, {
+    double reservePressure = DivePlanState.kDefaultReservePressureBar,
+  }) : _defaultReservePressure = reservePressure,
+       super(_createInitialState(reservePressure: reservePressure));
 
-  static DivePlanState _createInitialState() {
+  static DivePlanState _createInitialState({
+    double reservePressure = DivePlanState.kDefaultReservePressureBar,
+  }) {
     final now = DateTime.now();
     return DivePlanState(
       id: _uuid.v4(),
       name: 'New Dive Plan',
       segments: [],
       tanks: [_createDefaultTank()],
+      reservePressure: reservePressure,
       createdAt: now,
       updatedAt: now,
     );
@@ -72,7 +81,7 @@ class DivePlanNotifier extends StateNotifier<DivePlanState> {
 
   /// Reset to a new empty plan.
   void newPlan() {
-    state = _createInitialState();
+    state = _createInitialState(reservePressure: _defaultReservePressure);
   }
 
   /// Load an existing plan for editing.
@@ -282,6 +291,15 @@ class DivePlanNotifier extends StateNotifier<DivePlanState> {
     );
   }
 
+  /// Update reserve pressure in bar.
+  void updateReservePressure(double reservePressure) {
+    state = state.copyWith(
+      reservePressure: reservePressure,
+      isDirty: true,
+      updatedAt: DateTime.now(),
+    );
+  }
+
   // --------------------------------------------------------------------------
   // Repetitive Dive Support
   // --------------------------------------------------------------------------
@@ -365,7 +383,12 @@ class DivePlanNotifier extends StateNotifier<DivePlanState> {
 final divePlanNotifierProvider =
     StateNotifierProvider<DivePlanNotifier, DivePlanState>((ref) {
       final calculator = ref.watch(planCalculatorServiceProvider);
-      return DivePlanNotifier(calculator);
+      final pressureUnit = ref.read(pressureUnitProvider);
+      // Default reserve: 50 bar for metric, 500 psi (~34.47 bar) for imperial
+      final reservePressure = pressureUnit == PressureUnit.psi
+          ? PressureUnit.psi.convert(500, PressureUnit.bar)
+          : DivePlanState.kDefaultReservePressureBar;
+      return DivePlanNotifier(calculator, reservePressure: reservePressure);
     });
 
 // ============================================================================
@@ -387,6 +410,7 @@ final planResultsProvider = Provider<PlanResult>((ref) {
     segments: state.segments,
     tanks: state.tanks,
     sacRate: state.sacRate,
+    reservePressure: state.reservePressure,
     initialTissueState: state.initialTissueState,
   );
 });

lib/features/dive_planner/presentation/widgets/gas_results_panel.dart

@@ -64,8 +64,13 @@ class GasResultsPanel extends ConsumerWidget {
               )
             else
               ...results.gasConsumptions.map(
-                (consumption) =>
-                    _GasConsumptionCard(consumption: consumption, units: units),
+                (consumption) => _GasConsumptionCard(
+                  consumption: consumption,
+                  reservePressure: ref
+                      .watch(divePlanNotifierProvider)
+                      .reservePressure,
+                  units: units,
+                ),
               ),
           ],
         ),
@@ -76,9 +81,14 @@ class GasResultsPanel extends ConsumerWidget {
 
 class _GasConsumptionCard extends StatelessWidget {
   final GasConsumption consumption;
+  final double reservePressure;
   final UnitFormatter units;
 
-  const _GasConsumptionCard({required this.consumption, required this.units});
+  const _GasConsumptionCard({
+    required this.consumption,
+    required this.reservePressure,
+    required this.units,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -239,9 +249,7 @@ class _GasConsumptionCard extends StatelessWidget {
                   const SizedBox(width: 4),
                   Text(
                     context.l10n.divePlanner_warning_belowMinReserve(
-                      units.formatPressure(
-                        consumption.minGasReserve?.toDouble(),
-                      ),
+                      units.formatPressure(reservePressure),
                     ),
                     style: theme.textTheme.bodySmall?.copyWith(
                       color: theme.colorScheme.error,