feat(immich): per-album scheduled/memory dispatch + template tooling

Dispatch: honor {kind}_collection_mode on TrackingConfig — "per_collection"
fans out one event per album; "combined" pools assets as before. Extract
build_immich_dispatch_events shared by cron and test paths.

Assets: collect_scheduled_assets attaches album_name/album_url/album_public_url
to each asset so combined-mode templates can attribute rows to their source
album. Default scheduled_assets templates render a multi-album header with
inline album list and per-row album link; memory_mode follows the same pattern.

UI: "Reset to default" buttons on notification and command template slots
(per-slot and whole-template), backed by new GET /*-template-configs/defaults
endpoints. tracking-configs "Preview template" now opens an inline preview
modal with locale tabs instead of navigating away; Edit button deep-links
with ?edit_slot=<name> so the destination auto-opens the config and scrolls
to the slot. Reset confirmations use ConfirmModal instead of window.confirm.

Fixes:
* NotificationDispatcher._session_ctx infinite recursion when no shared
  aiohttp.ClientSession was passed — broke test dispatch for periodic/
  scheduled/memory (cron path was unaffected).
* telegram-bots /chats/{id}/test now resolves chat.language_override /
  language_code instead of using the raw ?locale query param, matching
  the resolution the tracker-target test endpoint already used.
* scheduled_assets default template no longer emits a blank line between
  header and the first asset when the multi-album branch is taken.

packages/server/src/notify_bridge_server/api/providers.py

@@ -426,19 +426,45 @@ async def get_album_shared_links(
     return []
 
 
+class CreateSharedLinkRequest(BaseModel):
+    """Options for POST /shared-links.
+
+    ``replace=True`` deletes every existing link for the album before creating
+    the new one, which is the only way to repair an expired or password-
+    protected link in the Immich API (there is no in-place "reset" endpoint).
+    Default ``False`` preserves the original additive behaviour used by the
+    "auto-create missing links" flow.
+    """
+
+    replace: bool = False
+
+
 @router.post("/{provider_id}/albums/{album_id}/shared-links")
 async def create_album_shared_link(
     provider_id: int,
     album_id: str,
+    body: CreateSharedLinkRequest | None = None,
     user: User = Depends(get_current_user),
     session: AsyncSession = Depends(get_session),
 ):
-    """Auto-create a public shared link for an album."""
+    """Auto-create a public shared link for an album.
+
+    With ``replace=True`` existing links for the album are deleted first, so
+    expired/password-protected links are effectively recycled into a fresh
+    public one.
+    """
     provider = await _get_user_provider(session, provider_id, user.id)
 
     if provider.type == "immich":
         http_session = await get_http_session()
         immich = make_immich_provider(http_session, provider)
+        if body and body.replace:
+            # Best-effort delete; if any delete fails we still try to create —
+            # the user will see the new link co-exist alongside the old one,
+            # which is better than a hard failure that leaves them stuck.
+            existing = await immich.client.get_shared_links(album_id)
+            for link in existing:
+                await immich.client.delete_shared_link(link.id)
         success = await immich.client.create_shared_link(album_id)
         if success:
             return {"success": True}