Add support for adding caller Namespace even if it's not in list of allowed Namespace options for Nexus endpoint

[laurakwhit]

Description & motivation 💭

• Updates the /nexus/{endpoint} page so Description isn't pushed to bottom if Allowed Caller Namespaces are defined.
• Adds allowCustomValue prop to Combobox that lets users type and add values not present in the predefined options list.
• Enables allowCustomValue on the Allowed Caller Namespaces field in the Nexus endpoint form, so users can specify Namespaces that they don't have access to (and therefore aren't listed).
• Validates a Namespace exists if it is added as a custom value in the Allowed Caller Namespaces field

Screenshots (if applicable) 📸

Nexus Endpoint Details Page

Allowed Caller Namespaces Input

Validate Namespace Error

Design Considerations 🎨

Testing 🧪

How was this tested 👻

• Manual testing
• E2E tests added
• Unit tests added

Steps for others to test: 🚶🏽‍♂️🚶🏽‍♀️

On Cloud > Navigate to a Nexus endpoint create/edit form

• Type a custom Namespace in the Allowed Caller Namespaces field
  • Verify the "Add" option should appear
• Press Enter or click the "Add" option
  • Verify it should be added and appear as selected in the dropdown
• Deselect the custom value by clicking it in the list
  • Verify it remains available for re-selection
• Verify selecting from the dropdown should still work as before
• Type an exact match of an existing option
  • Verify no "Add" option should appear
• Submit the form (with a custom Namespace that does not exist)
  • Verify it errors
• Submit the form (with a custom Namespace that does exist, but that isn't part of the default list and you don't have access to)
  • Verify it is successful

Checklists

Draft Checklist

Merge Checklist

Issue(s) closed

DT-3533

Docs

Any docs updates needed?

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Project	Deployment	Actions	Updated (UTC)
holocene	Ready	Preview, Comment	Apr 23, 2026 7:37pm

[temporal-cicd]

• ⚠️ Type 'null' is not assignable to type 'string'.

[temporal-cicd]

Warnings

⚠️

📊 Strict Mode: 16 errors in 5 files (1.6% of 1001 total) src/lib/holocene/menu/menu-item.svelte (2) L54:4: Type 'null' is not assignable to type 'string'. L55:4: Type 'null' is not assignable to type 'string'. src/lib/holocene/combobox/combobox.svelte (10) L152:4: Type 'null' is not assignable to type 'string'. L155:4: Type 'null' is not assignable to type '"action" | "activity" | "add-square" | "add" | "apple" | "archives" | "arrow-down" | "arrow-left" | "arrow-up" | "arrow-right" | "ascending" | "astronaut" | "aws" | "batch-operation" | ... 141 more ... | "xmark-square"'. L157:4: Type 'null' is not assignable to type 'keyof T'. L241:4: 'inputElement' is possibly 'null'. L242:4: 'inputElement' is possibly 'null'. L248:14: Argument of type 'string | T | undefined' is not assignable to parameter of type 'string | T'. L253:14: Argument of type 'string | T | undefined' is not assignable to parameter of type 'string | T'. L297:60: Function lacks ending return statement and return type does not include 'undefined'. L390:10: Type 'HTMLLIElement | null' is not assignable to type 'HTMLLIElement'. L390:43: 'menuElement' is possibly 'null'. src/lib/pages/nexus-form.svelte (1) L159:8: Type '{}' is not assignable to type 'string'. src/lib/holocene/combobox/combobox.stories.svelte (1) L275:6: Element implicitly has an 'any' type because expression of type '"action"' can't be used to index type '{}'. src/lib/pages/nexus-endpoint.svelte (2) L97:27: 'allowedCallerNamespaces' is possibly 'undefined'. L108:8: Type 'string[] | undefined' is not assignable to type 'string[]'.

Generated by 🚫 dangerJS against 57725b1

[temporal-cicd]

• ⚠️ 'allowedCallerNamespaces' is possibly 'undefined'.

[temporal-cicd]

• ⚠️ Type 'string[] | undefined' is not assignable to type 'string[]'.