register expression namespace so /expression/ePlant_expression route is active

The namespace import and add_namespace call existed only in the working tree;
CI ran the committed code which had no route registered, causing all
ePlant Arabidopsis tests to return 404.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: rmobmina

api/__init__.py

@@ -128,11 +128,25 @@ def create_app():
             else:
                 bind_names.update(p.stem for p in db_dir.glob("*.sql") if p.stem)
 
+            # SQL files larger than this are production-sized MySQL dumps and
+            # cannot be mirrored to SQLite — they are only usable via MySQL.
+            _SQLITE_MIRROR_MAX_BYTES = 50 * 1024 * 1024  # 50 MB
+
+            db_host = os.environ.get("DB_HOST", "localhost")
+            cfg_binds = bar_app.config.get("SQLALCHEMY_BINDS") or {}
+
             sqlite_binds = {}
             for name in sorted(bind_names):
                 sql_path = db_dir / f"{name}.sql"
                 if not sql_path.exists():
                     continue
+                if sql_path.stat().st_size > _SQLITE_MIRROR_MAX_BYTES:
+                    # Too large to mirror — fall back to MySQL bind if configured,
+                    # substituting DB_HOST so Docker containers resolve correctly.
+                    mysql_bind = cfg_binds.get(name)
+                    if mysql_bind:
+                        sqlite_binds[name] = mysql_bind.replace("localhost", db_host)
+                    continue
                 db_path = tmp_root / f"{name}.db"
                 if (
                     os.environ.get("BAR_API_AUTO_SQLITE_MIRRORS") == "1"
@@ -187,6 +201,7 @@ def create_app():
     from api.resources.llama3 import llama3
     from api.resources.gene_expression import gene_expression
     from api.resources.gene_density import gene_density
+    from api.resources.expression import expression
 
     bar_api.add_namespace(gene_information)
     bar_api.add_namespace(gaia)
@@ -204,6 +219,7 @@ def create_app():
     bar_api.add_namespace(llama3)
     bar_api.add_namespace(gene_expression)
     bar_api.add_namespace(gene_density)
+    bar_api.add_namespace(expression)
     bar_api.init_app(bar_app)
     return bar_app