feat(topology): add GHC06 layout and deploy docs

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

topology_api/routes/snapshot.py

@@ -7,6 +7,33 @@ from topology_api.queries.snapshot_queries import (
 )
 
 snapshot_bp = Blueprint("snapshot", __name__)
+GHC06_LAYOUT_START = datetime.fromisoformat("2025-02-15T00:00:00+00:00")
+
+
+def _layout_key_for_snapshot(requested_mission, snapshot_at):
+    """Keep historical mission views pinned to their contemporary layout.
+
+    GHC-05 overlaps GHC-06 chronologically, so timestamp-only selection would
+    incorrectly redraw the GHC-05 terminal snapshot with the later expansion
+    layout. Explicit mission views therefore take precedence over time.
+    """
+    if requested_mission:
+        try:
+            mission_number = int(requested_mission.rsplit("-", 1)[-1])
+        except (TypeError, ValueError):
+            mission_number = None
+        return (
+            "engineering_overview_ghc06_v1"
+            if mission_number is not None and mission_number >= 6
+            else None
+        )
+
+    snapshot_dt = datetime.fromisoformat(snapshot_at.replace("Z", "+00:00"))
+    return (
+        "engineering_overview_ghc06_v1"
+        if snapshot_dt >= GHC06_LAYOUT_START
+        else None
+    )
 
 
 def _parse_iso_timestamp(value):
@@ -82,7 +109,8 @@ def get_snapshot(base_code):
         })
 
     data = fetch_snapshot(snapshot_at)
-    layout = fetch_layout()
+    layout_key = _layout_key_for_snapshot(requested_mission, snapshot_at)
+    layout = fetch_layout(layout_key=layout_key)
 
     return jsonify({
         "base": data["base"],