Jun 26 MT-1 phase

config.py

@@ -31,6 +31,27 @@ class Config:
     SQLALCHEMY_TRACK_MODIFICATIONS = False
     SQLALCHEMY_ECHO = False
 
+    # ── Multi-tenancy (MT-1) ─────────────────────────────────────────────────
+    # Master switch. When False (default) the app behaves EXACTLY as the
+    # single-tenant deployment: no Host resolution, every query uses
+    # SQLALCHEMY_DATABASE_URI. Flip to True only after tenants are registered
+    # in the control plane (see MULTI_TENANT_PLAN.md). The control plane env
+    # vars (CONTROL_DATABASE_URL, CONTROL_FERNET_KEY) are only required when
+    # this is True.
+    MULTI_TENANT_ENABLED = os.environ.get(
+        'MULTI_TENANT_ENABLED', 'false'
+    ).strip().lower() in ('1', 'true', 'yes', 'on')
+    # Path prefixes that bypass the tenant gate even when enabled (e.g. health
+    # checks). '/static/' is always exempt. Comma-separated in the environment.
+    MULTI_TENANT_EXEMPT_PATHS = [
+        p.strip() for p in os.environ.get('MULTI_TENANT_EXEMPT_PATHS', '').split(',')
+        if p.strip()
+    ]
+    # Per-tenant SQLAlchemy engine pool tuning (see MULTI_TENANT_PLAN.md §4).
+    TENANT_ENGINE_POOL_SIZE    = int(os.environ.get('TENANT_ENGINE_POOL_SIZE', 5))
+    TENANT_ENGINE_MAX_OVERFLOW = int(os.environ.get('TENANT_ENGINE_MAX_OVERFLOW', 5))
+    TENANT_ENGINE_POOL_RECYCLE = int(os.environ.get('TENANT_ENGINE_POOL_RECYCLE', 1800))
+
     # ── File uploads ────────────────────────────────────────────────────────
     UPLOAD_FOLDER = os.path.join(basedir, 'app/static/uploads')
     MAX_CONTENT_LENGTH = 50 * 1024 * 1024   # 50 MB