Timer implemented. No working tests.

specs/requirements.md

@@ -29,7 +29,7 @@ The system relies on JWT-based authentication.
     *   **Input**: Email, Password.
     *   **Logic**:
         *   Email must be unique.
-        *   Creates a `UserProfile` with default values (e.g., default weight 70kg) upon account creation.
+        *   Creates a `UserProfile` with default values (e.g., default weight 70kg, default rest timer 120s) upon account creation.
         *   Sets `isFirstLogin` to true.
 *   **3.1.3 First-Time Setup (Password Change)**
     *   **Trigger**: If `User.isFirstLogin` is true.
@@ -50,6 +50,7 @@ Users can structure their training via Plans.
         *   User selects exercises from the global/personal library.
         *   **Ordering**: Exercises must be ordered (0-indexed).
         *   **Weighted Flag**: specific exercises in a plan can be marked as `isWeighted` (visual indicator).
+        *   **Rest Time**: specific exercises can have a defined `restTime` (seconds).
     *   **Logic**: Supports reordering capabilities via drag-and-drop in UI.
 *   **3.2.2 Plan Deletion**
     *   Standard soft or hard delete (Cascades to PlanExercises).
@@ -98,7 +99,32 @@ The core feature. States: **Idle**, **Active Session**, **Sporadic Mode**.
         *   `POST /sessions/quick-log/set`:
             *   Finds OR Creates the daily Quick Log session.
             *   Appends the set.
-    *   **UI**: Separate "Sporadic Mode" view specialized for fast, one-off entries without a timer or plan context.
+    *   **UI**: Separate "Sporadic Mode" view specialized for fast, one-off entries without a timer or plan context. Matches "Free Session" timer logic (see 3.4.3).
+
+*   **3.4.3 Rest Timer**
+    *   **Concept**: A configurable timer to track rest periods between sets.
+    *   **Contexts**:
+        *   **Free Session / Quick Log**:
+            *   Manual setup.
+            *   Default value: 2 minutes (120s).
+            *   **Persistence**: The last manually set value becomes the new default for the user.
+        *   **Planned Session**:
+            *   **Config**: Each step in a plan can have a specific `restTime` (seconds).
+            *   **Auto-Set**: When a set is logged, the timer resets to the value defined for the *current* step.
+            *   **Fallback**: If plan step has no `restTime`, use User's default.
+    *   **Behavior**:
+        *   **Start**: Manual trigger by user.
+        *   **Countdown**: Visual display.
+        *   **Completion**:
+            *   Audio signal (3 seconds).
+            *   Visual alert (Red color for 3 seconds).
+            *   Auto-reset to next expected rest time.
+    *   **UI Component**:
+        *   Floating Action Button (FAB).
+        *   **Idle**: Green Icon.
+        *   **Running**: Shows digits.
+        *   **Finished**: Red animation.
+
 
 ### 3.5. History & Analysis
 *   **3.5.1 Session History**