Add multi-tenant configuration support with dynamic module enabling

MULTITENANT_INTEGRATION.md

@@ -322,6 +322,32 @@ INVENTAR_WORKER_CONNECTIONS=100
 
 ---
 
+## Schul-Konfiguration pro Tenant
+
+Die Datei `config.json` unterstützt jetzt einen `tenants`-Block. Damit kann jede Schule eigene Modul-Schalter bekommen, ohne dass das ganze System global umgestellt werden muss.
+
+```json
+{
+    "tenants": {
+        "schule1": {
+            "modules": {
+                "library": { "enabled": true },
+                "student_cards": { "enabled": false }
+            }
+        },
+        "schule2": {
+            "modules": {
+                "library": { "enabled": false }
+            }
+        }
+    }
+}
+```
+
+Wenn ein Request über Subdomain oder `X-Tenant-ID` aufgelöst wird, liest die App diese Werte automatisch aus und blendet die Bibliothek bzw. andere Module nur für diesen Tenant ein oder aus.
+
+---
+
 ## Support & Debugging
 
 **Fragen?**

Web/settings.py

@@ -157,8 +157,36 @@ SSL_KEY = _get(_conf, ['ssl', 'key'], DEFAULTS['ssl']['key'])
 SCHOOL_PERIODS = _get(_conf, ['schoolPeriods'], DEFAULTS['schoolPeriods'])
 
 # Optional feature modules
-LIBRARY_MODULE_ENABLED = bool(_get(_conf, ['modules', 'library', 'enabled'], DEFAULTS['modules']['library']['enabled']))
-STUDENT_CARDS_MODULE_ENABLED = bool(_get(_conf, ['modules', 'student_cards', 'enabled'], DEFAULTS['modules']['student_cards']['enabled']))
+TENANT_CONFIGS = _get(_conf, ['tenants'], {})
+
+
+class _TenantAwareBool:
+    def __init__(self, module_name, default):
+        self.module_name = module_name
+        self.default = bool(default)
+
+    def resolve(self):
+        try:
+            from tenant import is_tenant_module_enabled
+            return bool(is_tenant_module_enabled(self.module_name, default=self.default))
+        except Exception:
+            return self.default
+
+    def __bool__(self):
+        return self.resolve()
+
+    def __int__(self):
+        return int(self.resolve())
+
+    def __str__(self):
+        return 'True' if self.resolve() else 'False'
+
+    def __repr__(self):
+        return f"_TenantAwareBool(module_name={self.module_name!r}, value={self.resolve()!r})"
+
+
+LIBRARY_MODULE_ENABLED = _TenantAwareBool('library', _get(_conf, ['modules', 'library', 'enabled'], DEFAULTS['modules']['library']['enabled']))
+STUDENT_CARDS_MODULE_ENABLED = _TenantAwareBool('student_cards', _get(_conf, ['modules', 'student_cards', 'enabled'], DEFAULTS['modules']['student_cards']['enabled']))
 STUDENT_DEFAULT_BORROW_DAYS = int(_get(_conf, ['modules', 'student_cards', 'default_borrow_days'], DEFAULTS['modules']['student_cards']['default_borrow_days']))
 STUDENT_MAX_BORROW_DAYS = int(_get(_conf, ['modules', 'student_cards', 'max_borrow_days'], DEFAULTS['modules']['student_cards']['max_borrow_days']))
 

Web/tenant.py

@@ -10,11 +10,43 @@ Each tenant can support up to 20+ users with isolated data and resource pools.
 from flask import request, g, has_request_context
 from functools import wraps
 import logging
+import settings as cfg
 
 logger = logging.getLogger(__name__)
 
 # Tenant registry: maps subdomain/tenant_id to database name
 TENANT_REGISTRY = {}
+if isinstance(getattr(cfg, 'TENANT_CONFIGS', None), dict):
+    TENANT_REGISTRY.update(cfg.TENANT_CONFIGS)
+
+
+def _get_nested_value(source, path, default=None):
+    current = source
+    for key in path:
+        if isinstance(current, dict) and key in current:
+            current = current[key]
+        else:
+            return default
+    return current
+
+
+def get_tenant_config(tenant_id=None):
+    """Return the registered config for a tenant, falling back to default."""
+    if tenant_id is None:
+        ctx = get_tenant_context()
+        tenant_id = ctx.tenant_id if ctx and ctx.tenant_id else 'default'
+
+    if tenant_id in TENANT_REGISTRY:
+        return TENANT_REGISTRY[tenant_id] or {}
+
+    return TENANT_REGISTRY.get('default', {}) or {}
+
+
+def is_tenant_module_enabled(module_name, tenant_id=None, default=False):
+    """Resolve whether a feature module is enabled for the current tenant."""
+    config = get_tenant_config(tenant_id)
+    enabled = _get_nested_value(config, ['modules', module_name, 'enabled'], default)
+    return bool(enabled)
 
 
 class TenantContext:
@@ -27,6 +59,7 @@ class TenantContext:
         self.tenant_id = None
         self.db_name = None
         self.subdomain = None
+        self.config = {}
 
     def resolve_tenant(self):
         """
@@ -40,6 +73,7 @@ class TenantContext:
         tenant_from_header = request.headers.get('X-Tenant-ID', '').strip()
         if tenant_from_header:
             self.tenant_id = tenant_from_header
+            self.config = get_tenant_config(tenant_from_header)
             return self._get_db_name(tenant_from_header)
 
         # Priority 2: Subdomain extraction
@@ -56,10 +90,12 @@ class TenantContext:
             if potential_subdomain not in ('www', 'api', 'admin', 'app', 'mail'):
                 self.subdomain = potential_subdomain
                 self.tenant_id = potential_subdomain
+                self.config = get_tenant_config(potential_subdomain)
                 return self._get_db_name(potential_subdomain)
 
         # Fallback to default tenant if no subdomain detected
         self.tenant_id = 'default'
+        self.config = get_tenant_config('default')
         return self._get_db_name('default')
 
     def _get_db_name(self, tenant_id):

config.json

@@ -50,6 +50,8 @@
         }
     },
 
+    "tenants": {},
+
     "allowed_extensions": [
         "png", "jpg", "jpeg", "gif",
         "hevc", "heif",