chore: merge origin/main (v1.37.0.0 split-engine gbrain) + bump to v1.38.0.0

Main shipped v1.37.0.0 (split-engine gbrain) while this PR was in review.
Merge resolved cleanly on bin/gstack-artifacts-init (allowlist patterns from
both branches coexist). CHANGELOG entry retained for our changes, version
header bumped from 1.36.0.0 to 1.38.0.0. Migration script renamed:
gstack-upgrade/migrations/v1.36.0.0.sh -> v1.38.0.0.sh, with internal
references and the test file updated to match.

VERSION + package.json: 1.38.0.0.
Regenerated SKILL.md across 12 hosts and refreshed golden fixtures.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

bin/gstack-artifacts-init

@@ -234,6 +234,11 @@ retros/*.md
 developer-profile.json
 builder-journey.md
 builder-profile.jsonl
+# Transcripts staged in remote-http MCP mode (per plan D11 split-engine).
+# gstack-memory-ingest persists per-run dirs here when local gbrain import
+# is skipped; brain admin pulls + indexes into the remote brain.
+transcripts/run-*/*.md
+transcripts/run-*/**/*.md
 # NOT synced (machine-local UX state):
 #   projects/*/question-preferences.json (per-machine UX preferences)
 #   projects/*/question-log.jsonl (audit/derivation log stays with preferences)
@@ -255,7 +260,9 @@ cat > "$GSTACK_HOME/.brain-privacy-map.json" <<'EOF'
   {"pattern": "builder-journey.md", "class": "artifact"},
   {"pattern": "projects/*/timeline.jsonl", "class": "behavioral"},
   {"pattern": "developer-profile.json", "class": "behavioral"},
-  {"pattern": "builder-profile.jsonl", "class": "behavioral"}
+  {"pattern": "builder-profile.jsonl", "class": "behavioral"},
+  {"pattern": "transcripts/run-*/*.md", "class": "behavioral"},
+  {"pattern": "transcripts/run-*/**/*.md", "class": "behavioral"}
 ]
 EOF