feat: webhook payload history — store and display recent incoming payloads

Backend:
- WebhookPayloadLog model (provider_id, method, headers, body, status, extracted_fields, error_message)
- Auto-log payloads in generic_webhook() with matched/unmatched/error status
- Auto-prune beyond max_stored_payloads per provider
- Header filtering (only Content-Type, User-Agent, X-* stored; no Authorization)
- GET/DELETE /api/providers/{id}/webhook-logs endpoints
- store_payloads + max_stored_payloads in WebhookProviderConfig

Frontend:
- WebhookPayloadHistory.svelte — expandable log viewer with status badges, JSON body, headers, extracted fields
- payloadHistory flag on webhook provider descriptor
- max_stored_payloads config field (0 = disabled)
- Password confirmation field on change password modal
- i18n keys for webhook logs (en + ru)

packages/server/src/notify_bridge_server/database/models.py

@@ -545,6 +545,22 @@ class ActionExecution(SQLModel, table=True):
     trigger: str = Field(default="scheduled")  # "scheduled", "manual", "dry_run"
 
 
+class WebhookPayloadLog(SQLModel, table=True):
+    """Log of incoming webhook payloads for debugging and replay."""
+
+    __tablename__ = "webhook_payload_log"
+
+    id: int | None = Field(default=None, primary_key=True)
+    provider_id: int = Field(foreign_key="service_provider.id", index=True)
+    method: str = Field(default="POST")
+    headers: dict[str, Any] = Field(default_factory=dict, sa_column=Column(JSON))
+    body: dict[str, Any] = Field(default_factory=dict, sa_column=Column(JSON))
+    status: str = Field(default="matched")  # "matched" | "unmatched" | "error"
+    extracted_fields: dict[str, Any] = Field(default_factory=dict, sa_column=Column(JSON))
+    error_message: str = Field(default="")
+    created_at: datetime = Field(default_factory=_utcnow)
+
+
 class AppSetting(SQLModel, table=True):
     """Key-value app-level settings (admin-configurable)."""