fix: merge main branch and renumber migration 027→037

Resolve 3 merge conflicts and renumber the automation_hooks migration
to follow main's migration chain (036_add_document_translation_fields).

Conflicts resolved:
- app/api/__init__.py: add automation_router alongside main's new routers
- app/utils/settings_service.py: add automation_hooks_enabled alongside compliance_enabled
- tests/conftest.py: add AutomationHook alongside AuditLog/ComplianceTemplate imports

Migration renumbered:
- 027_add_automation_hooks → 037_add_automation_hooks
- down_revision: 026_add_scheduled_jobs → 036_add_document_translation_fields

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/views/base.py

@@ -11,7 +11,17 @@ from sqlalchemy.orm import Session  # noqa: F401
 
 from app.auth import require_login  # noqa: F401
 from app.config import settings
-from app.database import get_db  # noqa: F401
+from app.database import SessionLocal, get_db  # noqa: F401
+from app.models import UserProfile
+from app.utils.i18n import (
+    SUPPORTED_LANGUAGES,
+    detect_language,
+    format_date,
+    format_datetime,
+    format_number,
+    get_suggested_languages,
+    translate,
+)
 
 # Set up Jinja2 templates
 templates_dir = Path(__file__).parent.parent.parent / "frontend" / "templates"
@@ -21,10 +31,58 @@ templates = Jinja2Templates(directory=str(templates_dir))
 templates.env.globals["min"] = min
 templates.env.globals["max"] = max
 
+# ---------------------------------------------------------------------------
+# i18n Jinja2 integration
+# ---------------------------------------------------------------------------
+# The _() function is available in every template to translate UI strings.
+# Usage: {{ _("nav.dashboard") }} or {{ _("upload.max_size", size="10 MB") }}
+# The locale is automatically resolved from the request context.
+# A default English implementation is registered as a global so error handlers
+# that don't go through _inject_global_context still have the function available.
+# ---------------------------------------------------------------------------
+
+templates.env.globals["supported_languages"] = SUPPORTED_LANGUAGES
+templates.env.globals["_"] = lambda key, **kwargs: translate(key, "en", **kwargs)
+
 # Customize Jinja2Templates to include app_version in all templates
 original_template_response = templates.TemplateResponse
 
 
+def _hydrate_language_from_db(request: Request, session_user: object) -> None:
+    """Load the user's preferred language from the DB into the session.
+
+    Called once per session when ``preferred_language`` is not yet in the
+    session.  A lightweight DB query fetches the stored preference so that
+    :func:`detect_language` picks it up from the session on all subsequent
+    requests without further DB access.
+    """
+    from app.utils.i18n import SUPPORTED_LANGUAGE_CODES
+
+    user_id: str | None = None
+    if isinstance(session_user, dict):
+        user_id = (
+            session_user.get("sub")
+            or session_user.get("preferred_username")
+            or session_user.get("email")
+            or session_user.get("id")
+        )
+    elif isinstance(session_user, str):
+        user_id = session_user
+
+    if not user_id:
+        return
+
+    db = SessionLocal()
+    try:
+        profile = db.query(UserProfile).filter(UserProfile.user_id == user_id).first()
+        if profile and profile.preferred_language and profile.preferred_language in SUPPORTED_LANGUAGE_CODES:
+            request.session["preferred_language"] = profile.preferred_language
+    except Exception:  # noqa: BLE001 — intentionally broad; DB may be temporarily unavailable
+        logger.debug("Could not hydrate language preference for user_id=%s", user_id)
+    finally:
+        db.close()
+
+
 def _inject_global_context(ctx: dict) -> None:
     """Inject shared global variables into every template context dict."""
     ctx.setdefault("version", settings.version)
@@ -48,8 +106,43 @@ def _inject_global_context(ctx: dict) -> None:
             session_user = req.session.get("user")
         # When auth is disabled every visitor is effectively "logged in"
         ctx.setdefault("is_logged_in", not getattr(settings, "auth_enabled", True) or session_user is not None)
+
+        # --- Hydrate session language from DB (once per session) ---
+        # If the session doesn't have a preferred_language yet but the user
+        # is logged in, load the stored preference from the database so that
+        # detect_language() picks it up from the session on this and all
+        # subsequent requests.
+        if hasattr(req, "session") and "preferred_language" not in req.session and session_user is not None:
+            _hydrate_language_from_db(req, session_user)
+
+        # --- i18n: detect language and register template helpers ---
+        current_locale = detect_language(req)
+        ctx.setdefault("current_locale", current_locale)
+
+        # Smart language suggestions for the compact nav-bar dropdown (5-7 languages)
+        accept_header = req.headers.get("accept-language", "") if hasattr(req, "headers") else ""
+        ctx.setdefault("suggested_languages", get_suggested_languages(current_locale, accept_header))
+
+        def _translate(key: str, **kwargs: object) -> str:
+            return translate(key, current_locale, **kwargs)
+
+        def _format_date(value: object, short: bool = False) -> str:
+            return format_date(value, current_locale, short=short)  # type: ignore[arg-type]
+
+        def _format_datetime(value: object) -> str:
+            return format_datetime(value, current_locale)  # type: ignore[arg-type]
+
+        def _format_number(value: object) -> str:
+            return format_number(value, current_locale)  # type: ignore[arg-type]
+
+        ctx.setdefault("_", _translate)
+        ctx.setdefault("format_date_l10n", _format_date)
+        ctx.setdefault("format_datetime_l10n", _format_datetime)
+        ctx.setdefault("format_number_l10n", _format_number)
     else:
         ctx.setdefault("is_logged_in", not getattr(settings, "auth_enabled", True))
+        ctx.setdefault("current_locale", "en")
+        ctx.setdefault("_", lambda key, **kw: translate(key, "en", **kw))
 
 
 def template_response_with_version(*args, **kwargs):