Delete orders + federation sx_components.py — rendering inlined to routes

Phase 2 (Orders):
- Checkout error/return renders moved directly into route handlers
- Removed orphaned test_sx_helpers.py

Phase 3 (Federation):
- Auth pages use _render_social_auth_page() helper in routes
- Choose-username render inlined into identity routes
- Timeline/search/follow/interaction renders inlined into social routes
  using serializers imported from sxc.pages
- Added _social_page() to sxc/pages/__init__.py for shared use
- Home page renders inline in app.py

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

orders/tests/test_sx_helpers.py

@@ -1,32 +0,0 @@
-"""Unit tests for orders sx component helpers."""
-from __future__ import annotations
-
-import pytest
-
-from orders.sx.sx_components import _status_pill_cls
-
-
-class TestStatusPillCls:
-    def test_paid(self):
-        result = _status_pill_cls("paid")
-        assert "emerald" in result
-
-    def test_Paid_uppercase(self):
-        result = _status_pill_cls("Paid")
-        assert "emerald" in result
-
-    def test_failed(self):
-        result = _status_pill_cls("failed")
-        assert "rose" in result
-
-    def test_cancelled(self):
-        result = _status_pill_cls("cancelled")
-        assert "rose" in result
-
-    def test_pending(self):
-        result = _status_pill_cls("pending")
-        assert "stone" in result
-
-    def test_unknown(self):
-        result = _status_pill_cls("refunded")
-        assert "stone" in result