Suppress /Workspace prefix diff for experiment names in direct deployment (#4627)

## Summary
- Use `OverrideChangeDesc` to suppress the `/Workspace` prefix diff on
experiment names, matching the Terraform provider's
`experimentNameSuppressDiff` behavior
- Fix test server `ExperimentUpdate` to strip `/Workspace` prefix,
matching cloud behavior
- Add acceptance test coverage for both `/Workspace/Users/...` and
`/Users/...` path forms
- Resolves #4285
#4324 

## Why?
The backend always strips the `/Workspace` prefix from experiment names,
so remote returns `/Users/...` while the config has
`/Workspace/Users/...`. Instead of mutating the config value (stripping
the prefix in `ApplyPresets`), we suppress the diff during change
detection via `OverrideChangeDesc` — the same approach the Terraform
provider uses with its
[`experimentNameSuppressDiff`](https://github.com/databricks/terraform-provider-databricks/blob/8945a7b2328659b1fc976d04e32457305860131f/mlflow/resource_mlflow_experiment.go#L13)
function.

Without this fix you get a persistent drift:
```
        "name": {
          "action": "update",
          "old": "/Workspace/Users/shreyas.goenka@databricks.com/test-experiment-bundle",
          "new": "/Workspace/Users/shreyas.goenka@databricks.com/test-experiment-bundle",
          "remote": "/Users/shreyas.goenka@databricks.com/test-experiment-bundle"
        },
```

## Test plan
- [x] Acceptance test `bundle/deployment/bind/experiment` verifies plan
shows 0 changes with `/Workspace/Users/...` path
- [x] Same test verifies plan shows 0 changes with `/Users/...` path
(without `/Workspace` prefix)
- [x] `bundle/resources/experiments/basic` acceptance test still passes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: shreyas-goenka

acceptance/bundle/deployment/bind/experiment/out.get.direct.json

@@ -0,0 +1,14 @@
+{
+  "plan": {
+    "resources.experiments.experiment1": {
+      "action": "skip",
+      "name_change": {
+        "action": "skip",
+        "reason": "alias",
+        "old": "/Workspace/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
+        "new": "/Workspace/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
+        "remote": "/Users/[USERNAME]/test-experiment[UNIQUE_NAME]"
+      }
+    }
+  }
+}

acceptance/bundle/deployment/bind/experiment/out.get.terraform.json

@@ -0,0 +1,8 @@
+{
+  "plan": {
+    "resources.experiments.experiment1": {
+      "action": "skip",
+      "name_change": null
+    }
+  }
+}

acceptance/bundle/deployment/bind/experiment/out.plan1.direct.json

@@ -0,0 +1,14 @@
+{
+  "plan": {
+    "resources.experiments.experiment1": {
+      "action": "skip",
+      "name_change": {
+        "action": "skip",
+        "reason": "remote_already_set",
+        "old": "/Workspace/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
+        "new": "/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
+        "remote": "/Users/[USERNAME]/test-experiment[UNIQUE_NAME]"
+      }
+    }
+  }
+}

acceptance/bundle/deployment/bind/experiment/out.plan1.terraform.json

@@ -0,0 +1,8 @@
+{
+  "plan": {
+    "resources.experiments.experiment1": {
+      "action": "skip",
+      "name_change": null
+    }
+  }
+}

acceptance/bundle/deployment/bind/experiment/out.plan2.direct.json

@@ -11,6 +11,10 @@ Updating deployment state...
 Deployment complete!
 
 >>> [CLI] experiments get-experiment [NUMID]
+{
+  "name": "/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
+  "lifecycle_stage": "active"
+}
 
 >>> [CLI] bundle deployment unbind experiment1
 Updating deployment state...
@@ -22,6 +26,10 @@ Deleting files...
 Destroy complete!
 
 >>> [CLI] experiments get-experiment [NUMID]
+{
+  "name": "/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
+  "lifecycle_stage": "active"
+}
 
 === Test cleanup:
 === Delete the pre-defined experiment: 0

acceptance/bundle/deployment/bind/experiment/out.plan2.terraform.json

@@ -17,12 +17,22 @@ trace $CLI bundle deployment bind experiment1 ${EXPERIMENT_ID} --auto-approve
 
 trace $CLI bundle deploy --force-lock --auto-approve
 
-trace $CLI experiments get-experiment ${EXPERIMENT_ID} | jq '{name: .experiment.name, lifecycle_stage: .experiment.lifecycle_stage}' > out.get.$DATABRICKS_BUNDLE_ENGINE.json
+# Plan should show no changes with /Workspace/Users/... path in config.
+# Use --output json to verify the change details including skip reason.
+# Write per-engine output since direct includes change details that terraform doesn't.
+# Filter to only the name change (tags/artifact_location may differ between local and cloud).
+$CLI bundle plan --output json | jq '{plan: .plan | map_values({action, name_change: (.changes.name // null)})}' > out.plan1.$DATABRICKS_BUNDLE_ENGINE.json
+
+trace $CLI experiments get-experiment ${EXPERIMENT_ID} | jq '{name: .experiment.name, lifecycle_stage: .experiment.lifecycle_stage}'
+
+# Now change the config to use /Users/... path (without /Workspace prefix).
+# Plan should still show no changes because the diff is suppressed.
+EXPERIMENT_NAME="//Users/${CURRENT_USER_NAME}/test-experiment$UNIQUE_NAME"
+envsubst < databricks.yml.tmpl > databricks.yml
+$CLI bundle plan --output json | jq '{plan: .plan | map_values({action, name_change: (.changes.name // null)})}' > out.plan2.$DATABRICKS_BUNDLE_ENGINE.json
 
 trace $CLI bundle deployment unbind experiment1
 
 trace $CLI bundle destroy --auto-approve
 
-trace $CLI experiments get-experiment ${EXPERIMENT_ID} | jq '{name: .experiment.name, lifecycle_stage: .experiment.lifecycle_stage}' > out.get2.$DATABRICKS_BUNDLE_ENGINE.json
-diff out.get.$DATABRICKS_BUNDLE_ENGINE.json out.get2.$DATABRICKS_BUNDLE_ENGINE.json
-rm out.get2.$DATABRICKS_BUNDLE_ENGINE.json
+trace $CLI experiments get-experiment ${EXPERIMENT_ID} | jq '{name: .experiment.name, lifecycle_stage: .experiment.lifecycle_stage}'

acceptance/bundle/deployment/bind/experiment/out.test.toml

@@ -1,10 +1,2 @@
-Badness = "Difference in GET request between direct and terraform; In direct, the prefix is /Workspace/Users, in TF it is /Users"
 Local = true
-
-# Fails on Cloud with:
-#=== CONT  TestAccept/bundle/deployment/bind/experiment/DATABRICKS_BUNDLE_ENGINE=direct
-#                                -  "name": "/Workspace/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
-#                                +  "name": "/Users/[USERNAME]/test-experiment[UNIQUE_NAME]",
-# https://github.com/databricks/cli/issues/4285
-
-Cloud = false
+Cloud = true