Fix A() component

Replaced single `url` parameter with explicit `url_name` (URL pattern name resolved via `reverse()`) and `href` (literal path). Fixes:
- Silent fallback (typos like `"ad_puchase"` silently became broken links) → now raises `NoReverseMatch` at render time
- `type(url) is str` gate → removed (implicit dual-mode eliminated entirely)
- Callable parameter (`url: Callable`) dead code → removed
- Implicit dual-mode (`url="name"` vs `url=reverse("name")`) → `url_name` vs `href` are now mutually exclusive params
- Inconsistent type annotation mixing `Callable` with string default → cleaned up
- Added `ValueError` when both `url_name` and `href` are provided
- Updated all 10 call sites across 6 view files and internal callers (`LinkedPurchase()`, `NameWithIcon()`)

games/views/session.py

@@ -81,7 +81,7 @@ def list_sessions(request: HttpRequest, search_string: str = "") -> HttpResponse
                     Div(
                         children=[
                             A(
-                                url="add_session",
+                                url_name="add_session",
                                 children=Button(
                                     icon=True,
                                     size="xs",
@@ -89,7 +89,7 @@ def list_sessions(request: HttpRequest, search_string: str = "") -> HttpResponse
                                 ),
                             ),
                             A(
-                                url=reverse(
+                                href=reverse(
                                     "list_sessions_start_session_from_session",
                                     args=[last_session.pk],
                                 ),