feat(integrations): add per-user OAuth wizard with user-mode for Dropbox, OneDrive, Google Drive

- Add user_mode to dropbox/onedrive/google_drive setup views that loads integration config
- Show user-friendly auth wizard when integration_id is provided (user mode)
- In user mode: show integration name, current folder, back-to-integrations link
- In callback templates: only save credentials (not config) for user integrations
- In integrations dashboard: show Authorize/Re-Authorize button for all OAuth types
- Add WATCH_FOLDER OAuth support: detect source_type in config for auth button
- isOAuthType() and oauthLink() now accept full integration object

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

app/views/dropbox.py

@@ -2,33 +2,82 @@
 Dropbox integration views for setup and OAuth callback.
 """
 
-from fastapi import Query, Request
+import json
 
-from app.views.base import APIRouter, require_login, settings, templates
+from fastapi import Query, Request
+from sqlalchemy.orm import Session
+
+from app.models import UserIntegration
+from app.utils.user_scope import get_current_owner_id
+from app.views.base import APIRouter, Depends, get_db, require_login, settings, templates
 
 router = APIRouter()
 
 
 @router.get("/dropbox-setup")
 @require_login
-async def dropbox_setup_page(request: Request, integration_id: int | None = Query(None)):
+async def dropbox_setup_page(
+    request: Request,
+    integration_id: int | None = Query(None),
+    db: Session = Depends(get_db),
+):
     """
     Setup page for the Dropbox integration.
-    Shows configuration status and setup instructions.
+
+    When ``integration_id`` is provided the page operates in **user mode**:
+    the OAuth wizard saves credentials to the named per-user integration
+    record rather than to the global application settings.  Only the folder
+    path from the integration's existing config is pre-populated; global
+    admin credentials are never exposed in this mode.
     """
-    # Check Dropbox configuration
+    if integration_id is not None:
+        owner_id = get_current_owner_id(request)
+        integration = (
+            db.query(UserIntegration)
+            .filter(UserIntegration.id == integration_id, UserIntegration.owner_id == owner_id)
+            .first()
+        )
+        if integration:
+            cfg: dict = {}
+            if integration.config:
+                try:
+                    cfg = json.loads(integration.config)
+                except (json.JSONDecodeError, TypeError):
+                    cfg = {}
+            # Support both "folder" (DROPBOX destination) and "folder_path" (WATCH_FOLDER source)
+            folder_path = cfg.get("folder", cfg.get("folder_path", ""))
+            return templates.TemplateResponse(
+                "dropbox.html",
+                {
+                    "request": request,
+                    "user_mode": True,
+                    "is_configured": bool(integration.credentials),
+                    "integration_id": integration_id,
+                    "integration_name": integration.name,
+                    "integration_type": integration.integration_type,
+                    "folder_path": folder_path,
+                    "app_key_value": "",
+                    "app_secret_value": "",
+                    "refresh_token_value": "",
+                },
+            )
+
+    # ── Admin / global mode ──────────────────────────────────────────────────
     is_configured = bool(settings.dropbox_app_key and settings.dropbox_app_secret and settings.dropbox_refresh_token)
 
     return templates.TemplateResponse(
         "dropbox.html",
         {
             "request": request,
+            "user_mode": False,
             "is_configured": is_configured,
             "app_key_value": settings.dropbox_app_key or "",
             "app_secret_value": settings.dropbox_app_secret if settings.dropbox_app_secret else "",
             "refresh_token_value": settings.dropbox_refresh_token if settings.dropbox_refresh_token else "",
-            "folder_path": settings.dropbox_folder or "/Documents/Uploads",  # Default folder path
+            "folder_path": settings.dropbox_folder or "/Documents/Uploads",
             "integration_id": integration_id,
+            "integration_name": None,
+            "integration_type": None,
         },
     )