chore: remove tor from startos core

Tor is being moved from a built-in OS feature to a service. This removes
the Arti-based Tor client, onion address management, hidden service
creation, and all related code from the core backend, frontend, and SDK.

- Delete core/src/net/tor/ module (~2060 lines)
- Remove OnionAddress, TorSecretKey, TorController from all consumers
- Remove HostnameInfo::Onion and HostAddress::Onion variants
- Remove onion CRUD RPC endpoints and tor subcommand
- Remove tor key handling from account and backup/restore
- Remove ~12 tor-related Cargo dependencies (arti-client, torut, etc.)
- Remove tor UI components, API methods, mock data, and routes
- Remove OnionHostname and tor patterns/regexes from SDK
- Add v0_4_0_alpha_20 database migration to strip onion data
- Bump version to 0.4.0-alpha.20

sdk/base/lib/osBindings/ErrorData.ts

@@ -1,3 +1,3 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 
-export type ErrorData = { details: string; debug: string }
+export type ErrorData = { details: string; debug: string; info: unknown }

sdk/base/lib/osBindings/Host.ts

@@ -5,7 +5,6 @@ import type { PublicDomainConfig } from './PublicDomainConfig'
 
 export type Host = {
   bindings: { [key: number]: BindInfo }
-  onions: string[]
   publicDomains: { [key: string]: PublicDomainConfig }
   privateDomains: Array<string>
   /**

sdk/base/lib/osBindings/HostnameInfo.ts

@@ -1,8 +1,10 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { GatewayInfo } from './GatewayInfo'
 import type { IpHostname } from './IpHostname'
-import type { OnionHostname } from './OnionHostname'
 
-export type HostnameInfo =
-  | { kind: 'ip'; gateway: GatewayInfo; public: boolean; hostname: IpHostname }
-  | { kind: 'onion'; hostname: OnionHostname }
+export type HostnameInfo = {
+  kind: 'ip'
+  gateway: GatewayInfo
+  public: boolean
+  hostname: IpHostname
+}

sdk/base/lib/osBindings/OnionHostname.ts

@@ -1,7 +0,0 @@
-// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
-
-export type OnionHostname = {
-  value: string
-  port: number | null
-  sslPort: number | null
-}

sdk/base/lib/osBindings/index.ts

@@ -149,7 +149,6 @@ export { NetInfo } from './NetInfo'
 export { NetworkInfo } from './NetworkInfo'
 export { NetworkInterfaceInfo } from './NetworkInterfaceInfo'
 export { NetworkInterfaceType } from './NetworkInterfaceType'
-export { OnionHostname } from './OnionHostname'
 export { OsIndex } from './OsIndex'
 export { OsVersionInfoMap } from './OsVersionInfoMap'
 export { OsVersionInfo } from './OsVersionInfo'