Remove widget system — fully replaced by fragment composition

Delete shared/contracts/widgets.py, shared/services/widget_registry.py,
and shared/services/widgets/ (empty stubs). Remove register_all_widgets()
from factory and widgets Jinja global from jinja_setup. Zero consumers
remain — all cross-app UI composition now uses the fragment API.

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

shared/services/widget_registry.py

@@ -1,90 +0,0 @@
-"""Singleton widget registry for cross-domain UI composition.
-
-Usage::
-
-    from shared.services.widget_registry import widgets
-
-    # Register at app startup (after domain services)
-    widgets.add_container_nav(NavWidget(...))
-
-    # Query in templates / context processors
-    for w in widgets.container_nav:
-        ctx = await w.context_fn(session, container_type="page", ...)
-"""
-from __future__ import annotations
-
-from shared.contracts.widgets import (
-    NavWidget,
-    CardWidget,
-    AccountPageWidget,
-    AccountNavLink,
-)
-
-
-class _WidgetRegistry:
-    """Central registry holding all widget descriptors.
-
-    Widgets are added at startup and read at request time.
-    Properties return sorted-by-order copies.
-    """
-
-    def __init__(self) -> None:
-        self._container_nav: list[NavWidget] = []
-        self._container_card: list[CardWidget] = []
-        self._account_pages: list[AccountPageWidget] = []
-        self._account_nav: list[AccountNavLink] = []
-
-    # -- registration ---------------------------------------------------------
-
-    def add_container_nav(self, w: NavWidget) -> None:
-        self._container_nav.append(w)
-
-    def add_container_card(self, w: CardWidget) -> None:
-        self._container_card.append(w)
-
-    def add_account_page(self, w: AccountPageWidget) -> None:
-        self._account_pages.append(w)
-        # Auto-create a matching internal nav link
-        slug = w.slug
-
-        def _href(s=slug):
-            from shared.infrastructure.urls import account_url
-            return account_url(f"/{s}/")
-
-        self._account_nav.append(AccountNavLink(
-            label=w.label,
-            order=w.order,
-            href_fn=_href,
-            external=False,
-        ))
-
-    def add_account_link(self, link: AccountNavLink) -> None:
-        self._account_nav.append(link)
-
-    # -- read access (sorted copies) ------------------------------------------
-
-    @property
-    def container_nav(self) -> list[NavWidget]:
-        return sorted(self._container_nav, key=lambda w: w.order)
-
-    @property
-    def container_cards(self) -> list[CardWidget]:
-        return sorted(self._container_card, key=lambda w: w.order)
-
-    @property
-    def account_pages(self) -> list[AccountPageWidget]:
-        return sorted(self._account_pages, key=lambda w: w.order)
-
-    @property
-    def account_nav(self) -> list[AccountNavLink]:
-        return sorted(self._account_nav, key=lambda w: w.order)
-
-    def account_page_by_slug(self, slug: str) -> AccountPageWidget | None:
-        for w in self._account_pages:
-            if w.slug == slug:
-                return w
-        return None
-
-
-# Module-level singleton — import this everywhere.
-widgets = _WidgetRegistry()

shared/services/widgets/__init__.py

@@ -1,22 +0,0 @@
-"""Per-domain widget registration.
-
-Called once at startup after domain services are registered.
-Only registers widgets for domains that are actually available.
-"""
-from __future__ import annotations
-
-
-def register_all_widgets() -> None:
-    from shared.services.registry import services
-
-    if services.has("calendar"):
-        from .calendar_widgets import register_calendar_widgets
-        register_calendar_widgets()
-
-    if services.has("market"):
-        from .market_widgets import register_market_widgets
-        register_market_widgets()
-
-    if services.has("cart"):
-        from .cart_widgets import register_cart_widgets
-        register_cart_widgets()

shared/services/widgets/calendar_widgets.py

@@ -1,10 +0,0 @@
-"""Calendar-domain widgets.
-
-All calendar widgets have been replaced by fragments
-(events app serves them at /internal/fragments/).
-"""
-from __future__ import annotations
-
-
-def register_calendar_widgets() -> None:
-    pass

shared/services/widgets/cart_widgets.py

@@ -1,10 +0,0 @@
-"""Cart-domain widgets.
-
-Account nav link has been replaced by fragments
-(cart app serves account-nav-item at /internal/fragments/).
-"""
-from __future__ import annotations
-
-
-def register_cart_widgets() -> None:
-    pass

shared/services/widgets/market_widgets.py

@@ -1,10 +0,0 @@
-"""Market-domain widgets.
-
-Container nav widgets have been replaced by fragments
-(market app serves them at /internal/fragments/).
-"""
-from __future__ import annotations
-
-
-def register_market_widgets() -> None:
-    pass