fix(server): improve self hosted usability (#15510)

fix #15505
fix #15502
fix #15496
fix #15491

#### PR Dependency Tree


* **PR #15510** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Added configurable delays for invitations, invite links, and document
publishing by newly created accounts.
- Added workspace action checks that explain blocked actions and retry
timing.
- BYOK setup now verifies model capabilities and saves only validated
options.

- **Bug Fixes**
- Improved BYOK probing for chat, structured responses, tool calls,
embeddings, reranking, and image generation.
  - Preserved probe request order and strengthened response validation.
  - Authentication configuration changes now reload correctly.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/native/index.d.ts

@@ -34,6 +34,7 @@ export declare class BackendRuntime {
   claimInviteAbuseAction(actionId: string, workerId: string): Promise<boolean>
   claimRetryableInviteAbuseActions(workerId: string, limit: number): Promise<Array<RuntimeInviteAbuseClaimedAction>>
   markInviteAbuseAction(actionId: string, workerId: string, status: string, error?: string | undefined | null): Promise<boolean>
+  evaluateWorkspaceActionV1(actorUserId: string, workspaceId: string): Promise<RuntimeWorkspaceActionDecision>
   assertWorkspaceInviteQuotaV1(input: RuntimeWorkspaceInviteQuotaInput): Promise<RuntimeWorkspaceInviteQuotaDecision>
   commitWorkspaceInviteQuotaV1(reservationId: string, usage: RuntimeWorkspaceInviteQuotaUsage): Promise<boolean>
   releaseWorkspaceInviteQuotaV1(reservationId: string): Promise<boolean>
@@ -1496,6 +1497,12 @@ export interface RuntimeVerificationTokenRecord {
   expiresAtMs: number
 }
 
+export interface RuntimeWorkspaceActionDecision {
+  allowed: boolean
+  retryAfterSeconds?: number
+  reason?: string
+}
+
 export interface RuntimeWorkspaceArtifact {
   id: string
   workspaceId: string