docs(act-obs-flow): added action and observation flow documentation

Author: khaledmohamed00

docs/docs_action_observation_flow/action_obersvation_flow.md

@@ -0,0 +1,132 @@
+# Action-Observation Flow 
+
+## wrapper Hierarchy 
+
+
+Vertical Order:
+
+- Top: Highest-level wrapper (first applied)
+
+- Bottom: Base environment
+
+Inheritance Notation:
+
+- Use (ParentClass) next to wrapper names
+
+Wrapping Notation
+
+- Show ← wraps arrows between layers
+<p align="center">
+  <img src="images/class_hierarchy.png" width="150"/>
+</p>
+
+## Flow
+1. **`RelativeActionSpace(ActionWrapper).step(act)`**
+   
+   -   2- Calls step function of ActionWrapper (→2)
+
+2. **`ActionWrapper.step(act)`**
+   - 3. Calls `RelativeActionSpace.action(act)`
+   - 4. Calls `GripperWrapper.step(act)`
+
+3. **`RelativeActionSpace.action(act)`**
+   - Processes action: `{"tquart": [0.01, 0, 0, 0, 0, 0, 1], "gripper": 0}`
+   - Operations:
+     - Clips action within min/max limits
+     - Makes action relative (current_pose + action)
+     - Updates `action["tquart"]`
+
+4. **`GripperWrapper(ActObsInfoWrapper).step(act)`**
+   - →5. Calls `GripperWrapper.action(act)`
+   - →6. Calls `CameraSetWrapper.step(act)`
+   - →15. Calls `GripperWrapper.observation(obs)`
+
+5. **`GripperWrapper.action(act)`**
+   - Uses `act["gripper"]` to open/close gripper
+   - Only executes if state change needed
+   - Deletes `"gripper"` key from action dict
+
+6. **`CameraSetWrapper(ActObsInfoWrapper).step(act)`**
+   - →7. Calls `CameraSetWrapper.action(act)`
+   - →8. Calls `CameraSetWrapper(ActObsInfoWrapper).step(act)`
+   - →14. Calls `CameraSetWrapper.observation(obs)`
+
+7. **`CameraSetWrapper.action(act)`**
+   - (Pass-through) Returns original action
+
+8. **`CameraSetWrapper(ActObsInfoWrapper).step(act)`**
+   - →9. Calls `CameraSetWrapper.action(act)`
+   - →10. Calls `FR3Sim.step(act)`
+
+9. **`CameraSetWrapper.action(act)`**
+   - (Pass-through) Returns original action
+
+10. **`FR3Sim.step(act)`**
+    - →11. Calls `FR3Env.step(act)`
+    - 13. Executes:
+      ```python
+      self.sim.step_until_convergence()
+      state = self.sim_robot.get_state()
+      ```
+    - Returns observation
+
+11. **`FR3Env.step(act)`**
+    - Sets new pose:
+      ```python
+      self.robot.set_cartesian_position(
+          common.Pose(
+              translation=action_dict[self.tquart_key][:3],
+              quaternion=action_dict[self.tquart_key][3:]
+          )
+      )
+      ```
+    - →12. Calls `FR3Env.get_obs()`
+
+12. **`FR3Env.get_obs()`**
+    - Returns:
+      ```python
+      (
+          tquart=np.concatenate([
+              self.robot.get_cartesian_position().translation(),
+              self.robot.get_cartesian_position().rotation_q()
+          ]),
+          joints=self.robot.get_joint_position(),
+          xyzrpy=self.robot.get_cartesian_position().xyzrpy()
+      )
+      ```
+    - Shapes:
+      - `joints`: (7,)
+      - `tquart`: (7,) [x,y,z, qx,qy,qz,qw]
+      - `xyzrpy`: (6,) [x,y,z, roll,pitch,yaw]
+
+14. **`CameraSetWrapper.observation(obs)`**
+    - Adds camera data:
+      ```python
+      {
+          ...original_obs...,
+          "frames": {
+              "wrist": {
+                  "rgb": (256,256,3),
+                  "depth": (256,256,3)
+              },
+              "default_free": {
+                  "wrist": {
+                      "rgb": (256,256,3),
+                      "depth": (256,256,3)
+                  }
+              }
+          }
+      }
+      ```
+
+15. **`GripperWrapper.observation(obs)`**
+    - Adds gripper state:
+      ```python
+      {
+          ...previous_data...,
+          "gripper": float
+      }
+      ```
+# Sequence Diagram
+![image](images/sequence_diagram.png)
+