feat: remove register, add evo webhooks, admin view-as user

- Remove /register route and nav links (users created via Evotor webhook)
- Fix evotor_webhooks.py: use phone=None instead of phone="" to avoid unique constraint
- Add admin "view as user" feature: POST /admin/users/{id}/view-as sets viewed_user_id
  in session; POST /admin/view-as/stop clears it
- catalog, vk_catalog, sync, connections GET routes use get_viewed_user() so admins
  see another user's data while browsing
- Orange banner shown at top when admin is viewing as another user

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/routes/vk_catalog.py

@@ -2,7 +2,7 @@ from fastapi import APIRouter, Depends, Request
 from fastapi.responses import HTMLResponse, RedirectResponse
 from sqlalchemy.orm import Session
 
-from web.auth.session import get_current_user
+from web.auth.session import get_viewed_user
 from web.config import settings
 from web.database import get_db
 from web.models.connections import VkCachedAlbum, VkCachedProduct, VkConnection
@@ -20,19 +20,20 @@ def _render(request: Request, template: str, ctx: dict) -> HTMLResponse:
 @router.get("/vk-catalog/albums")
 async def vk_catalog_albums(request: Request, db: Session = Depends(get_db)):
     try:
-        user = get_current_user(request, db)
+        real_user, viewed_user = get_viewed_user(request, db)
     except Exception:
         return RedirectResponse("/login", 303)
 
-    vk_conn = db.query(VkConnection).filter_by(user_id=user.id).first()
+    vk_conn = db.query(VkConnection).filter_by(user_id=viewed_user.id).first()
     albums = (
         db.query(VkCachedAlbum)
-        .filter(VkCachedAlbum.user_id == user.id)
+        .filter(VkCachedAlbum.user_id == viewed_user.id)
         .order_by(VkCachedAlbum.title)
         .all()
     )
     return _render(request, "vk_catalog/albums.html", {
-        "user": user,
+        "user": real_user,
+        "viewed_user": viewed_user if viewed_user.id != real_user.id else None,
         "albums": albums,
         "vk_conn": vk_conn,
         "refresh_interval": settings.CATALOG_REFRESH_INTERVAL_SECONDS,
@@ -42,22 +43,23 @@ async def vk_catalog_albums(request: Request, db: Session = Depends(get_db)):
 @router.get("/vk-catalog/albums/{album_id}/products")
 async def vk_catalog_products(album_id: str, request: Request, db: Session = Depends(get_db)):
     try:
-        user = get_current_user(request, db)
+        real_user, viewed_user = get_viewed_user(request, db)
     except Exception:
         return RedirectResponse("/login", 303)
 
-    album = db.query(VkCachedAlbum).filter_by(user_id=user.id, album_id=album_id).first()
+    album = db.query(VkCachedAlbum).filter_by(user_id=viewed_user.id, album_id=album_id).first()
     if not album:
         return RedirectResponse("/vk-catalog/albums", 303)
 
     products = (
         db.query(VkCachedProduct)
-        .filter(VkCachedProduct.user_id == user.id, VkCachedProduct.album_id == album_id)
+        .filter(VkCachedProduct.user_id == viewed_user.id, VkCachedProduct.album_id == album_id)
         .order_by(VkCachedProduct.name)
         .all()
     )
     return _render(request, "vk_catalog/products.html", {
-        "user": user,
+        "user": real_user,
+        "viewed_user": viewed_user if viewed_user.id != real_user.id else None,
         "album": album,
         "products": products,
     })