Gate “Create instance” button by application-level create permission

### Description

Optional

**Context / Problem**
The “Create instance” button on the instances page is shown based only on team role. It should also depend on whether the user has create permission in at least one application. This may require pre-loading a minimal application list that includes the user’s application role to evaluate eligibility.

**Acceptance criteria**
- The button is visible only if the user has create permission in at least one application within the current team context.
- If the user lacks create permission in all applications, the button is hidden.
- Evaluation uses application-level roles, not just team role.
- Implement a minimal preload (or cached fetch) of applications with the user’s role to perform the check without heavy payloads.

### Epic/Story

_No response_

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate