fix(dev-portal): potential unintended string replacement in context path generation

This issue addresses a technical concern raised during PR #3471 review regarding the string replacement logic in the `generatePathname` function.

**Concern:**
The fallback logic `currentPathname.replace(pathContextId, item.id)` could potentially replace unintended substrings if `pathContextId` appears multiple times in the pathname or as part of other path segments.

**Current Implementation:**
```typescript
const pathname =
context?.generatePathFromContext?.(item, currentPathname) ??
currentPathname.replace(pathContextId, item.id);
```

**Potential Issue:**
If a pathname contains the `pathContextId` as a substring in other parts of the path (not just the context segment), this could lead to incorrect URL generation.

**Suggested Solutions:**
1. Implement segment-by-segment path replacement
2. Use more robust path parsing logic
3. Add validation to ensure replacement only affects the intended context segment

**Related PR:** https://github.com/equinor/fusion-framework/pull/3471

**Priority:** Medium - Should be addressed before the next major version to prevent potential routing issues.