feat: connect Tiny through its v3 API with OAuth

Tiny v3 replaces the v2 token adapter. An operator connects Tiny once from
the Kanban; the callback is authorised by a single-use state, because Tiny's
cross-site redirect does not carry the SameSite=Strict operator cookie.
Tokens are kept in provider_tokens, the refresh token rotates under a row
lock, and the worker keeps the connection alive while order creation is off.

Orders find or create the customer's contact by CNPJ, then POST /pedidos
with product ids from TINY_PRODUCT_TEXTIL_FOLHA, _TEXTIL_AVULSA, _UV_FOLHA
and _UV_AVULSA and numeroOrdemCompra DTF-<number>; a retry searches the
customer's recent orders for that number first. The product settings avoid a
_FILE suffix, which the secrets loader reads as a secret file path.

Production passes the application credentials through but keeps
TINY_ADAPTER fake: Tiny has no sandbox, so creating real orders waits for a
supervised test. compose.providers.yaml gives the local API and worker an
internet route for provider testing; the default local stack still has none.

Verified with the full CI integration sequence locally, including the new
tiny_oauth_test against the real database.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/adapters.py

@@ -22,8 +22,10 @@ def require_runtime():
             raise RuntimeError(f'{name} must use the currently supported fake adapter')
     tiny = os.environ.get('TINY_ADAPTER')
     if tiny == 'tiny':
-        if not os.environ.get('TINY_TOKEN'):
-            raise RuntimeError('TINY_TOKEN is required for the Tiny adapter')
+        from .tiny import required_settings
+        for name in required_settings():
+            if not os.environ.get(name):
+                raise RuntimeError(f'{name} is required for the Tiny adapter')
     elif tiny != 'fake':
         raise RuntimeError('TINY must use the fake or tiny adapter')
     # Mercado Pago is selectable only with its credentials present; it has not