bundle: remove split config sync elements from every block

[ilyakuz-db]

Stack

	PR	What it does
1	#6117	Route each change to the one block that defines it
2	this PR	Removing an element defined in several blocks deletes it from each
3	#6134	A key change is written as a key rewrite in every defining block

Each PR is based on the one above it and carries the acceptance tests for its own behaviour.

Changes

Removes a keyed list element that is defined in more than one YAML block from every block that defines it.

The parent PR routes each change to a single block, which is right for a field edit but cannot express this removal: a job task declared both at the top level and in a targets.<target> override has a part in each, and the merged element only disappears once both are gone. That case was therefore left unapplied. routeElement now returns one destination per defining block, and ApplyChangesToYAML already groups changes by file, so the patch layer is unchanged.

# "both" is defined in each block; remote deletes the task
 resources: {jobs: {j: {tasks:
-  - task_key: both
-      max_retries: 2
   - task_key: keep}}}                 # survives
 targets: {dev: {resources: {jobs: {j:
-      tasks:
-        - task_key: both
-            timeout_seconds: 30
+      tasks: []

Each destination gets its own copy of the change, because the Replace→Add reclassification for a field absent from the source rewrites the operation, and one block's rewrite must not leak into the next.

Why

Leaving the change unapplied was safe but never converged: the element stays in configuration after the user deleted it remotely, so every later sync re-reports the same removal. Deleting only the top-level half — the behaviour before the parent PR — was worse, since it orphaned the override half.

Tests

Two new directories, both failing on the parent commit and passing here:

• split/keyed_remove — removes one task per block in one run (exactly those two go, beta survives), then removes the task defined in both blocks: task_key: both goes from 2 to 0 and the top-level keep task is untouched.
• split/isolation — a structural change to a split element alongside an unrelated scalar edit on another resource, in the same run. The unrelated edit is applied regardless, so one harder change never stops the rest.

Review with git diff -w. The real change is +39/−14 in resolve.go; the rest of the raw line count is re-indentation from wrapping the existing body in a per-destination loop.

[github-actions]

Approval status: pending

/acceptance/bundle/ - needs approval

8 files changed
Suggested: @pietern
Also eligible: @denik, @andrewnester, @anton-107, @janniklasrose, @lennartkats-db, @shreyas-goenka

/bundle/ - needs approval

Files: bundle/configsync/blockindex.go, bundle/configsync/resolve.go
Suggested: @pietern
Also eligible: @denik, @andrewnester, @anton-107, @janniklasrose, @lennartkats-db, @shreyas-goenka

_{Any maintainer (@andrewnester, @anton-107, @denik, @pietern, @shreyas-goenka, @simonfaltum, @renaudhartert-db, @janniklasrose, @lennartkats-db) can approve all areas.
See OWNERS for ownership rules.}

[eng-dev-ecosystem-bot]

Integration test report

Commit: 490a0da

Run: 30768921827

	Env	🔄​flaky	💚​RECOVERED	🙈​SKIP	✅​pass	🙈​skip	Time
🔄​	aws linux	2	4	4	320	1072	4:28
💚​	aws windows		4	4	324	1070	6:19
💚​	azure linux		4	4	322	1071	4:25
💚​	azure windows		4	4	324	1069	6:31
💚​	gcp linux		1	5	321	1073	4:11
💚​	gcp windows		1	5	323	1071	6:23

10 interesting tests: 4 RECOVERED, 4 SKIP, 2 flaky

	Test Name	aws linux	aws windows	azure linux	azure windows	gcp linux	gcp windows
💚​	TestAccept	💚​R	💚​R	💚​R	💚​R	💚​R	💚​R
🙈​	TestAccept/bundle/invariant/no_drift	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🙈​	TestAccept/bundle/resources/vector_search_endpoints/drift/recreated_same_name	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🙈​	TestAccept/bundle/resources/vector_search_indexes/recreate/embedding_dimension	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🙈​	TestAccept/ssh/connection	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🔄​	TestFsCpDirToDirFileNotOverwritten	🔄​f	✅​p	✅​p	✅​p	✅​p	✅​p
🔄​	TestFsCpDirToDirFileNotOverwritten/uc-volumes_to_uc-volumes	🔄​f	✅​p	✅​p	✅​p	✅​p	✅​p
💚​	TestFetchRepositoryInfoAPI_FromRepo	💚​R	💚​R	💚​R	💚​R	🙈​S	🙈​S
💚​	TestFetchRepositoryInfoAPI_FromRepo/root	💚​R	💚​R	💚​R	💚​R
💚​	TestFetchRepositoryInfoAPI_FromRepo/subdir	💚​R	💚​R	💚​R	💚​R

Top 3 slowest tests (at least 2 minutes):

duration	env	testname
5:21	gcp windows	TestAccept
5:15	aws windows	TestAccept
4:24	azure windows	TestAccept

[ilyakuz-db]

Consolidated into #6138 — the stack is merged into a single PR with the same final tree.