feat(auth): switch signup to OTP verification flow

Replace legacy signup with start/verify/resend endpoints, add OTP-focused mail templates and auth rate limits, and align compose/env/runbook for local self-hosted Supabase OTP behavior.

backend/src/core/config/settings.py

@@ -78,66 +78,6 @@ class CelerySettings(BaseModel):
     task_max_retries: int = 3
 
 
-class WebSettings(BaseModel):
-    server: Literal["uvicorn", "gunicorn"] = "gunicorn"
-    host: str = "0.0.0.0"
-    port: int = Field(default=8000, ge=1, le=65535)
-    reload: bool = False
-    workers: int = Field(default=2, ge=1, le=64)
-    worker_class: str = "uvicorn.workers.UvicornWorker"
-    timeout: int = Field(default=60, ge=1, le=600)
-    keepalive: int = Field(default=5, ge=1, le=120)
-    log_level: Literal["debug", "info", "warning", "error", "critical"] = "info"
-
-
-class GunicornSettings(BaseModel):
-    enabled_in_prod: bool = True
-    workers: int = 2
-    worker_class: str = "uvicorn.workers.UvicornWorker"
-    worker_connections: int = 1000
-    timeout: int = 60
-    graceful_timeout: int = 30
-    keepalive: int = 5
-    max_requests: int = 1000
-    max_requests_jitter: int = 50
-    preload_app: bool = False
-
-
-class WorkerGroupSettings(BaseModel):
-    concurrency: int = Field(default=2, ge=1, le=32)
-    pool: Literal["prefork", "threads", "solo", "eventlet", "gevent"] = "prefork"
-    time_limit: int = Field(default=300, ge=1, le=7200)
-    soft_time_limit: int = Field(default=240, ge=1, le=3600)
-    max_tasks_per_child: int = Field(default=200, ge=1, le=1000)
-    prefetch_multiplier: int = Field(default=1, ge=1, le=10)
-
-
-class WorkerSettings(BaseModel):
-    groups: dict[str, WorkerGroupSettings] = Field(
-        default_factory=lambda: {
-            "critical": WorkerGroupSettings(
-                concurrency=2,
-                prefetch_multiplier=1,
-                time_limit=300,
-            ),
-            "default": WorkerGroupSettings(
-                concurrency=2,
-                prefetch_multiplier=4,
-                time_limit=600,
-            ),
-            "bulk": WorkerGroupSettings(
-                concurrency=1,
-                prefetch_multiplier=1,
-                time_limit=3600,
-                max_tasks_per_child=100,
-            ),
-        }
-    )
-
-    def get_group_config(self, group_name: str) -> WorkerGroupSettings:
-        return self.groups.get(group_name, WorkerGroupSettings())
-
-
 class CorsSettings(BaseModel):
     allow_origins: list[str] = Field(
         default_factory=lambda: [
@@ -220,14 +160,11 @@ def _resolve_env_file() -> str:
 
 class Settings(BaseSettings):
     runtime: RuntimeSettings = RuntimeSettings()
-    web: WebSettings = WebSettings()
-    gunicorn: GunicornSettings = GunicornSettings()
     cors: CorsSettings = CorsSettings()
     redis: RedisSettings = RedisSettings()
     supabase: SupabaseSettings = SupabaseSettings()
     celery: CelerySettings = CelerySettings()
     database: DatabaseSettings = DatabaseSettings()
-    worker: WorkerSettings = WorkerSettings()
 
     @computed_field
     @property