fix: use app logic to avoid broken migration & apply DRY scidsg#622

When running ``make migrate-dev`` there's an error with the new
'host_organization' table migration. Filling & commiting the default
record on app startup if it's missing removes the error, reduces
repetition of magic constants which were given variable names in the
app, & avoids an incomplete DB state which breaks rendering of CSS.

Partial reversion of 9cad571

For Roadmap Item scidsg#533

hushline/__init__.py

@@ -93,7 +93,10 @@ def inject_user() -> dict[str, Any]:
 
     @app.context_processor
     def inject_host() -> dict[str, HostOrganization]:
-        return dict(host_org=HostOrganization.fetch_or_default())
+        if (host_org := HostOrganization.fetch()) is None:
+            db.session.add(host_org := HostOrganization())
+            db.session.commit()
+        return dict(host_org=host_org)
 
     @app.context_processor
     def inject_is_personal_server() -> dict[str, Any]:
@@ -109,17 +112,4 @@ def add_onion_location_header(response: Response) -> Response:
             )
             return response
 
-    # we can't
-    if app.config.get("FLASK_ENV", None) != "development":
-        with app.app_context():
-            try:
-                host_org = HostOrganization.fetch()
-            except ProgrammingError:
-                app.logger.warning(
-                    "Could not check for existence of HostOrganization", exc_info=True
-                )
-            else:
-                if host_org is None:
-                    app.logger.warning("HostOrganization data not found in database.")
-
     return app

migrations/versions/5410668e15ad_add_host_organization_table.py

@@ -26,11 +26,6 @@ def upgrade() -> None:
         sa.PrimaryKeyConstraint("id", name=op.f("pk_host_organization")),
     )
 
-    op.execute(
-        "INSERT INTO host_organization (id, brand_app_name, brand_primary_hex_color) "
-        "VALUES (1, '🤫 Hush Line', '#7d25c1')"
-    )
-
 
 def downgrade() -> None:
     op.drop_table("host_organization")