Allauth extracted to its own repository (~/dev/mizan-allauth)

The auth-provider concern becomes a dedicated Django system. Removed from
mizan: the Django integration (mizan/integrations/allauth — auth contexts
+ ~15 form wrappers), the legacy/ pre-kernel TypeScript client, the
allauth and webauthn dependency extras (fido2 was consumed only by the
WebAuthn form wrappers), and the HEADLESS_JWT_* settings fallbacks — the
allauth-headless compat seam belongs to the dedicated system, not to
mizan's JWT module. Duplicate-name registration in discovery now surfaces
a warning instead of passing silently. README claims updated to point at
mizan-allauth; the root README's hand-maintained status matrix collapsed
into the tests/afi conformance suite as the parity authority.
OWED_SURFACE.md refreshed against the post-extraction tree (22 units).

mizan-django suite: 350 passed, 21 skipped.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backends/mizan-django/README.md

@@ -7,8 +7,6 @@ function. Typed React client generated. Invalidation automatic.
 
 ```bash
 uv add "mizan[channels]"
-# or with allauth integration:
-uv add "mizan[channels,allauth]"
 ```
 
 ## Setup
@@ -116,6 +114,9 @@ class ContactForm(mizanFormMixin, forms.Form):
 Auto-registers `contact.schema`, `contact.validate`, `contact.submit`. Frontend
 gets `useContactForm()`.
 
+Auth-provider forms (django-allauth login, signup, MFA, WebAuthn) live in the
+dedicated `mizan-allauth` repository, built on this mixin.
+
 ## Channels
 
 WebSocket-native RPC via a flag flip: