feat: rotas de login/logoff (app/routers/auth.py)

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

app/routers/auth.py

@@ -0,0 +1,62 @@
+"""
+Rotas de login/logoff. O painel não usa mais HTTP Basic Auth (ver
+app/auth.py) — quem não está logado é redirecionado para GET /login pelo
+exception handler de NaoAutenticado (registrado em app/main.py).
+"""
+from typing import Optional
+from urllib.parse import urlencode
+
+from fastapi import APIRouter, Depends, Form, Request
+from fastapi.responses import HTMLResponse, RedirectResponse
+from fastapi.templating import Jinja2Templates
+
+from .. import session
+from ..auth import UsuarioLogado, autenticar_credenciais, exigir_login
+from ..csrf import exigir_csrf, token_do_contexto
+
+router = APIRouter()
+templates = Jinja2Templates(directory="app/templates")
+
+
+def _proximo_seguro(next_: Optional[str]) -> str:
+    """Só aceita um path interno (começa com "/", sem "//") — nunca uma URL
+    externa, para não virar um open redirect via POST /login?next=..."""
+    if next_ and next_.startswith("/") and not next_.startswith("//"):
+        return next_
+    return "/clientes"
+
+
+@router.get("/login", response_class=HTMLResponse)
+def form_login(request: Request, next: Optional[str] = None):
+    return templates.TemplateResponse(
+        request, "login.html", {"csrf_token": token_do_contexto(request), "next": next or ""}
+    )
+
+
+@router.post("/login", dependencies=[Depends(exigir_csrf)])
+def login(
+    request: Request,
+    usuario: str = Form(...),
+    senha: str = Form(...),
+    next: Optional[str] = Form(None),
+):
+    usuario_logado = autenticar_credenciais(usuario, senha)
+    if usuario_logado is None:
+        return templates.TemplateResponse(
+            request,
+            "login.html",
+            {"csrf_token": token_do_contexto(request), "next": next or "", "erro": "Usuário ou senha inválidos."},
+        )
+
+    destino = _proximo_seguro(next)
+    resposta = RedirectResponse(url=destino, status_code=303)
+    token = session.criar_token(usuario_logado.login, usuario_logado.nome, usuario_logado.perfil)
+    resposta.set_cookie(session.SESSION_COOKIE_NAME, token, httponly=True, samesite="lax")
+    return resposta
+
+
+@router.post("/logout", dependencies=[Depends(exigir_csrf)])
+def logout(usuario: UsuarioLogado = Depends(exigir_login)):
+    resposta = RedirectResponse(url="/login", status_code=303)
+    resposta.delete_cookie(session.SESSION_COOKIE_NAME)
+    return resposta

app/templates/login.html

@@ -0,0 +1,30 @@
+<!-- app/templates/login.html -->
+<!DOCTYPE html>
+<html lang="pt-BR">
+<head>
+  <meta charset="UTF-8">
+  <title>Entrar — Painel de Clientes</title>
+  <style>
+    body { font-family: system-ui, sans-serif; margin: 0; background: #17171a; color: #f4f4f5; display: flex; align-items: center; justify-content: center; min-height: 100vh; }
+    form { width: 320px; padding: 24px; background: #232326; border-radius: 10px; }
+    h1 { font-size: 1.2rem; margin-top: 0; }
+    label { display: block; margin-top: 10px; font-size: 0.85rem; color: #a1a1aa; }
+    input { width: 100%; padding: 8px; border-radius: 6px; border: 1px solid #3a3a3e; background: #17171a; color: #f4f4f5; box-sizing: border-box; }
+    button { margin-top: 16px; width: 100%; padding: 10px 16px; border: none; border-radius: 6px; background: #F5821F; color: #17171a; font-weight: 700; cursor: pointer; }
+    .mensagem.danger { padding: 10px; border-radius: 6px; margin-bottom: 12px; background: #7f1d1d; }
+  </style>
+</head>
+<body>
+  <form method="post" action="/login">
+    <h1>Painel de Clientes</h1>
+    {% if erro %}<div class="mensagem danger">{{ erro }}</div>{% endif %}
+    <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+    <input type="hidden" name="next" value="{{ next }}">
+    <label for="usuario">Usuário</label>
+    <input type="text" id="usuario" name="usuario" required autofocus>
+    <label for="senha">Senha</label>
+    <input type="password" id="senha" name="senha" required>
+    <button type="submit">Entrar</button>
+  </form>
+</body>
+</html>