Summary

Fixes a topology reload bug where downstream components whose input key stayed the same across reload would silently stop receiving events if the upstream producer changed kind (e.g. an enrichment-table-derived source at key X replaced by a regular source at key X, or a transform at X replaced by a source at X).

get_changed_outputs previously only iterated to_change sets, missing cross-type respawns. It now also considers keys that appear in (sources.to_remove ∪ transforms.to_remove ∪ enrichment_tables.to_remove) intersected with (sources.to_add ∪ transforms.to_add ∪ enrichment_tables.to_add).

Vector configuration

Reproducer config A (pre-reload):

sources:
  in:
    type: demo_logs
    format: json
    interval: 1

enrichment_tables:
  memory_table:
    type: memory
    ttl: 60
    inputs: ["in"]
    source_config:
      source_key: "shared"
      export_interval: 2

sinks:
  observer:
    type: console
    inputs: ["shared"]
    encoding:
      codec: json

Reloaded config B:

sources:
  shared:
    type: demo_logs
    format: json
    interval: 1

sinks:
  observer:
    type: console
    inputs: ["shared"]
    encoding:
      codec: json

How did you test this PR?

Manual end-to-end reproduction with ./target/debug/vector --config live.yaml, swapping A -> B via SIGHUP:

• On master: observer receives 0 events after reload (bug confirmed).
• On this branch: observer continues receiving demo_logs events after reload.

Also ran cargo check with the topology feature set. A unit-test-only regression could not be reliably reproduced in the current test harness (the reattach path fires but events don't flow via basic_source/basic_sink after reload — a separate test-infra issue), so the branch relies on the manual reproducer above. Happy to add a test if a reviewer knows a working scaffold.

Change Type

• Bug fix
• New feature
• Dependencies
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Changelog fragment added.
• No. A maintainer will apply the no-changelog label to this PR.

References

• Related: chore(enrichment tables): split component diffs #25712 (codex review comment that flagged the source/enrichment-table variant of this gap)