docs(experiments): document unarchive experiment functionality

contents/docs/experiments/managing-lifecycle.mdx

@@ -8,7 +8,7 @@ availability:
   enterprise: full
 ---
 
-After you've analyzed your experiment metrics and determined a winning variant, you can manage the experiment's lifecycle by ending, pausing, or resetting it.
+After you've analyzed your experiment metrics and determined a winning variant, you can manage the experiment's lifecycle by ending, pausing, archiving, or resetting it.
 
 ## Ending an experiment
 
@@ -32,7 +32,6 @@ Remember, experimentation is an iterative process. Each experiment teaches you s
 
 If you've already shipped a variant to 100% of users, you can still end the experiment using the **End experiment** button. In this case, the experiment is marked as complete without changing the feature flag.
 
-
 ## Pausing an experiment
 
 You can temporarily pause an experiment to stop collecting data without ending it completely. This is useful when:
@@ -53,13 +52,24 @@ Technically speaking it resets the experiment's start and end dates. All events
 
 This is useful when you need to restart data collection, for example after fixing a bug in your experiment setup or changing metric definitions.
 
-## Comparing pausing, ending, and resetting
+## Archiving and unarchiving experiments
+
+Archiving removes an experiment from the default list view but preserves all data, including start/end dates and results. This is useful for keeping your experiment list clean after you've finished analyzing an experiment.
+
+To archive an experiment, select **Archive experiment** from the **More** menu on the experiment detail page.
+
+If you need to restore an archived experiment, select **Unarchive experiment** from the **More** menu on either the experiment detail page or the experiments list. This restores the experiment to the default list view without losing any data.
+
+Unarchiving is different from [resetting](#resetting-analysis), which clears results and returns the experiment to a draft state.
+
+## Comparing lifecycle actions
 
 Here's how the actions differ:
 
-| Status | Feature flag | Users see | Exposure tracking | Results | Can resume |
-|--------|----------------------|----------|-----------|---------|---------|
-| **Running** | Enabled | Multiple variants | Continues | Updating | N/A |
-| **Pausing** | Disabled | Control variant | Stops | Fixed | Yes |
-| **Ending** | Modified to roll out chosen variant to all users | Chosen variant | Continues (chosen variant only) | Fixed | No |
-| **Resetting** | Unchanged | Multiple variants | Continues | Cleared | Yes (relaunch) |
+| Status        | Feature flag                                     | Users see             | Exposure tracking               | Results   | Can resume      |
+| ------------- | ------------------------------------------------ | --------------------- | ------------------------------- | --------- | --------------- |
+| **Running**   | Enabled                                          | Multiple variants     | Continues                       | Updating  | N/A             |
+| **Pausing**   | Disabled                                         | Control variant       | Stops                           | Fixed     | Yes             |
+| **Ending**    | Modified to roll out chosen variant to all users | Chosen variant        | Continues (chosen variant only) | Fixed     | No              |
+| **Resetting** | Unchanged                                        | Multiple variants     | Continues                       | Cleared   | Yes (relaunch)  |
+| **Archiving** | Unchanged                                        | Depends on flag state | Unchanged                       | Preserved | Yes (unarchive) |