Move aitools out of experimental/ to top-level aitools/

Per Simon's review on #4917, the source files should live outside
experimental/ now that aitools is a top-level command. Renames the
directory from experimental/aitools/ to aitools/ and updates all
import paths, examples, and tooling references (Makefile, OWNERS,
testmask, pr-checklist).

The experimental/aitools alias still routes to the same package via
its new import path, so 'databricks experimental aitools' continues
to work as a deprecated entry point.

Co-authored-by: Isaac

Author: jamesbroadhead

.agent/skills/pr-checklist/SKILL.md

@@ -59,5 +59,5 @@
 # Internal
 /internal/                  team:platform
 
-# Experimental
-/experimental/aitools/      team:eng-apps-devex @lennartkats-db
+# AI tools
+/aitools/                   team:eng-apps-devex @lennartkats-db

.github/OWNERS

@@ -243,7 +243,7 @@ bundle/direct/dresources/resources.generated.yml: ./bundle/direct/tools/generate
 
 .PHONY: test-exp-aitools
 test-exp-aitools:
-	make test TEST_PACKAGES="./experimental/aitools/..." ACCEPTANCE_TEST_FILTER="TestAccept/apps"
+	make test TEST_PACKAGES="./aitools/..." ACCEPTANCE_TEST_FILTER="TestAccept/apps"
 
 .PHONY: test-exp-ssh
 test-exp-ssh:

Makefile

@@ -12,9 +12,9 @@ import (
 	"sync"
 	"syscall"
 
+	"github.com/databricks/cli/aitools/lib/middlewares"
+	"github.com/databricks/cli/aitools/lib/session"
 	"github.com/databricks/cli/cmd/root"
-	"github.com/databricks/cli/experimental/aitools/lib/middlewares"
-	"github.com/databricks/cli/experimental/aitools/lib/session"
 	"github.com/databricks/cli/libs/cmdctx"
 	"github.com/databricks/cli/libs/cmdio"
 	"github.com/databricks/cli/libs/log"