fix(controller): preserve AllTargetsFiles change types for BUG-015

[sbalabanov]

Summary

Fix BUG-015 by preserving NEW and DELETED change types when an AllTargetsFiles global trigger changes.

Previously, global invalidation could overwrite every result as CHANGED. For example, if .bazelrc changes in the same revision that adds //service:new and deletes //service:old, callers must still receive NEW for the added target and DELETED for the removed target; only targets present in both revisions should be promoted to distance-zero CHANGED.

The fix applies the same classification behavior to chunk-backed and TGB-backed graph comparisons.

Test Plan

• Unit tests cover unchanged, hash-changed, added, and deleted targets for both graph formats.

Issues

T3-BUG-015

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[sbalabanov]

Simplify the PR description, include use case example of the bug the PR fixes

[sbalabanov]

Simplified the PR description and added a concrete .bazelrc example showing that a global trigger must preserve NEW and DELETED classifications while promoting only shared targets to CHANGED. Current HEAD: 1eeb5a17a9e527f6db6ad36ea5a67b60b10726fc.

[addressed by agent]

[xytan0056]

could you add an integration test for such behavior in
https://github.com/xytan0056/bazel-fixture/pulls
and expand the testcase here ?

[sbalabanov]

could you add an integration test for such behavior in https://github.com/xytan0056/bazel-fixture/pulls and expand the testcase here ?

why would the fixture go to a private fork?
I could add an integration test right in tango repo if needed, even though the change has a controller test already.

Also for e2e test, it might be a separate diff if we did not test all-in files before.