Setup contrib/ directory with CODEOWNERS that is extensible for non-SDK team extensions. (#2862)

* Move temporal-opentracing/ and temporal-spring-ai/ to extensions/, and add @temporalio/ai-sdk as a CODEOWNER of temporal-spring-ai/

* rename extensions -> contrib

* finish rename

Author: donald-pinckney

.github/CODEOWNERS

@@ -5,3 +5,11 @@
 # @temporalio/sdk will be requested for review when
 # someone opens a pull request.
 * @temporalio/sdk
+
+
+# Below are owners for modules in the contrib/ directory
+# that are owned by teams other than the SDK team.
+# For each one, we add the owning team, as well as
+# @temporalio/sdk, so the SDK team can continue to
+# manage repo-wide concerns
+/contrib/temporal-spring-ai/ @temporalio/ai-sdk @temporalio/sdk

.gitignore

@@ -6,7 +6,7 @@ target
 .idea
 .gradle
 /build
-/*/build
+**/build
 **/out
 /lib
 dummy
@@ -17,7 +17,7 @@ src/main/idls/*
 .project
 .settings
 .vscode/
-*/bin
+**/bin
 /.claude
 mise.local.toml
 **/.factorypath