[manjari25]

Why?

The tango analyzer asks a ChangedTargetsClient which targets a batch affects, but nothing implements it against the Tango service. This adds the OSS adapter.

What?

• tangoclient.New(client, Config{Remote, Strategy}) implements ChangedTargetsClient over Tango's YARPC client.
• Requests the base revision against the base plus the batch's change URIs, with max_distance: -1 so Tango doesn't keep only the seed targets.
• Keeps only each target's ID and distance while the response streams, then resolves labels from the metadata that closes it.
• Fails closed on a failed or cut-off stream, missing metadata, or a target with no label.
• Adds github.com/uber/tango at v0.0.46, which raises fx to 1.24 and dig to 1.19. MODULE.bazel gets a gazelle_override because Tango's Bazel files target its own workspace.

Test Plan

• Unit tests
• CI

Issue