Align compaction tests with always-skip post-layout

codex-rs/core/tests/suite/snapshots/all__suite__compact__pre_sampling_model_switch_compaction_shapes.snap

@@ -1,6 +1,6 @@
 ---
 source: core/tests/suite/compact.rs
-assertion_line: 1773
+assertion_line: 1460
 expression: "format_labeled_requests_snapshot(\"Pre-sampling compaction on model switch to a smaller context window: current behavior compacts using prior-turn history only (incoming user message excluded), and the follow-up request carries compacted history plus the new user message.\",\n&[(\"Initial Request (Previous Model)\", &requests[0]),\n(\"Pre-sampling Compaction Request\", &requests[1]),\n(\"Post-Compaction Follow-up Request (Next Model)\", &requests[2]),])"
 ---
 Scenario: Pre-sampling compaction on model switch to a smaller context window: current behavior compacts using prior-turn history only (incoming user message excluded), and the follow-up request carries compacted history plus the new user message.
@@ -22,10 +22,7 @@ Scenario: Pre-sampling compaction on model switch to a smaller context window: c
 06:message/user:<SUMMARIZATION_PROMPT>
 
 ## Post-Compaction Follow-up Request (Next Model)
-00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:before switch
-04:message/user:<COMPACTION_SUMMARY>\nPRE_SAMPLING_SUMMARY
-05:message/developer:<model_switch>\nThe user was previously using a different model....
-06:message/user:after switch
+00:message/user:before switch
+01:message/user:<COMPACTION_SUMMARY>\nPRE_SAMPLING_SUMMARY
+02:message/developer:<model_switch>\nThe user was previously using a different model....
+03:message/user:after switch

codex-rs/core/tests/suite/snapshots/all__suite__compact_remote__remote_mid_turn_compaction_multi_summary_shapes.snap

@@ -1,5 +1,6 @@
 ---
 source: core/tests/suite/compact_remote.rs
+assertion_line: 1896
 expression: "format_labeled_requests_snapshot(\"Remote mid-turn compaction after an earlier summary compaction: the older summary remains in model-visible history and round-trips into the next compact request.\",\n&[(\"Second Turn Request (Before Mid-Turn Compaction)\", &second_turn_request),\n(\"Remote Compaction Request\", &compact_request),])"
 ---
 Scenario: Remote mid-turn compaction after an earlier summary compaction: the older summary remains in model-visible history and round-trips into the next compact request.

codex-rs/core/tests/suite/snapshots/all__suite__compact_remote__remote_mid_turn_compaction_summary_only_shapes.snap

@@ -1,8 +1,9 @@
 ---
 source: core/tests/suite/compact_remote.rs
-expression: "format_labeled_requests_snapshot(\"Remote mid-turn compaction where compact output has only summary user content: continuation layout reinjects canonical context before that summary.\",\n&[(\"Remote Compaction Request\", &compact_request),\n(\"Remote Post-Compaction History Layout\", &post_compact_turn_request),])"
+assertion_line: 1790
+expression: "format_labeled_requests_snapshot(\"Remote mid-turn compaction where compact output has only summary user content: continuation layout keeps the summary-only compact output without inserting extra context items.\",\n&[(\"Remote Compaction Request\", &compact_request),\n(\"Remote Post-Compaction History Layout\", &post_compact_turn_request),])"
 ---
-Scenario: Remote mid-turn compaction where compact output has only summary user content: continuation layout reinjects canonical context before that summary.
+Scenario: Remote mid-turn compaction where compact output has only summary user content: continuation layout keeps the summary-only compact output without inserting extra context items.
 
 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>