fix(backend/copilot): skip --resume for DB-reconstructed transcripts

When the SDK encounters a baseline-written GCS transcript and correctly
discards it (mode != 'sdk'), it falls back to rebuilding context from
DB session messages via _session_messages_to_transcript. The previous
code then wrote this reconstructed transcript to disk and set
use_resume=True, but the Claude CLI rejected it with exit code 1 because
the TranscriptBuilder format uses synthetic IDs (msg_sdk_...) and lacks
required fields (sessionId, cwd, version) that the CLI needs for --resume.

Fix: reconstruction loads context into transcript_builder for state
tracking and uploads, but never writes to disk or sets use_resume=True.
Context is injected via the use_resume=False path in _build_query_message.

Add test assertion: result.use_resume is False after baseline reconstruction.

autogpt_platform/backend/backend/copilot/sdk/service.py

@@ -2489,43 +2489,21 @@ async def _restore_cli_session_for_turn(
         return result
 
     # No CLI session in GCS — reconstruct from DB messages as last-resort fallback.
+    # The reconstruction uses TranscriptBuilder synthetic IDs (msg_sdk_...) which
+    # are NOT compatible with the Claude CLI's --resume mechanism.  We load the
+    # reconstructed content into the transcript_builder so the current turn has
+    # accurate state for the post-turn upload, but we do NOT attempt --resume.
+    # Context for this turn is injected by _build_query_message (use_resume=False path).
     prior = session.messages[:-1]
     reconstructed = _session_messages_to_transcript(prior)
-    if reconstructed and sdk_cwd:
-        result.transcript_content = reconstructed
-        transcript_builder.load_previous(reconstructed, log_prefix=log_prefix)
-        result.transcript_msg_count = len(prior)
-        result.transcript_covers_prefix = True
-        # Write the reconstructed transcript to disk so the CLI can
-        # --resume on this turn (avoids context-free response and
-        # seeds the native session for cross-pod restore next turn).
-        _reconstructed_bytes = reconstructed.encode("utf-8")
-        if _write_cli_session_to_disk(
-            _reconstructed_bytes, sdk_cwd, session_id, log_prefix
-        ):
-            result.use_resume = True
-            result.resume_file = session_id
-            logger.info(
-                "%s Reconstructed transcript from %d session messages "
-                "and wrote to disk for --resume",
-                log_prefix,
-                len(prior),
-            )
-        else:
-            logger.info(
-                "%s Reconstructed transcript from %d session messages "
-                "(disk write failed — running without --resume this turn)",
-                log_prefix,
-                len(prior),
-            )
-    elif reconstructed:
+    if reconstructed:
         result.transcript_content = reconstructed
         transcript_builder.load_previous(reconstructed, log_prefix=log_prefix)
         result.transcript_msg_count = len(prior)
         result.transcript_covers_prefix = True
         logger.info(
             "%s Reconstructed transcript from %d session messages "
-            "(no sdk_cwd — running without --resume this turn)",
+            "(injecting context via message prefix — not using --resume)",
             log_prefix,
             len(prior),
         )

autogpt_platform/backend/backend/copilot/sdk/service_helpers_test.py

@@ -685,6 +685,9 @@ class TestRestoreCliSessionModeCheck:
         assert "BASELINE_SENTINEL" not in result.transcript_content
         # DB reconstruction from session.messages must have run instead
         assert "hello-unique-marker" in result.transcript_content
+        # use_resume must be False — reconstructed TranscriptBuilder JSONL uses
+        # synthetic IDs (msg_sdk_...) that the Claude CLI rejects for --resume
+        assert result.use_resume is False
 
     @pytest.mark.asyncio
     async def test_sdk_mode_transcript_allows_resume(self, tmp_path):