Make the Orbit UI copy correct and consistent before GA

What does this MR do and why?

Makes the Orbit UI text correct and consistent before GA. It applies the designer feedback from the monetization E2E run (https://gitlab.com/gitlab-org/orbit/knowledge-graph/-/work_items/1399#note_4047206753), aligns every Orbit UI string with the GitLab word list, and fixes the texts that were not true for the state where they show. It replaces !263732 (merged) and !263735 (closed) (one MR, as discussed).

• Designer feedback: no "not eligible" wording (Contact sales instead), Indexing paused for a group that is off after its trial, and the Group status tab is now Status.
• Word list: GitLab Orbit in every UI string, GitLab Credits, GitLab Duo, Contact sales, merge request, Select, top-level group, Admin Mode. Errors follow "Could not ... Try again.". The docs use the new UI labels.
• No "free": the trial texts say "trial", "Start trial", and "credits".
• Self-Managed: after the instance trial, GitLab Orbit keeps indexing and admins can still turn groups on (since !263080 (merged)), so the pages say so and no longer lock turning groups on. The Query editor gives an administrator an admin text. The admin card says "Credits used up" with no end date when the trial credits run out early.
• Other fixes: "Only top-level groups can be indexed." goes on :base (no "Root namespace" prefix), a queued group polls every 60 seconds, no placeholder text on the health card, and no "Not available" badge.

Not in this MR: plural forms with n__, the entity type names, and the claims that legal and pricing confirm.

Screenshots or screen recordings

These screenshots were taken before the "free" wording was removed; the overnight E2E run records the final texts on https://gitlab.com/gitlab-org/orbit/knowledge-graph/-/work_items/1399.

Designer feedback and Self-Managed pages

Before: the 2026-10-19 E2E run on master plus !263371 (merged). After: this branch. Full results: https://gitlab.com/gitlab-org/orbit/knowledge-graph/-/work_items/1399#note_4044909513

Scenario	Before	After
S1.1b: Group Orbit settings: a group that cannot start a free trial
S1.1b: Off page: no group can start a free trial
S2.2b: Status tab (was Group status): a group that is off after its trial
M3.2: Self-Managed admin page after the instance trial
M3.2: Self-Managed Status tab after the instance trial
M4.3a: Self-Managed overview: the instance cannot start a trial
M1.1: Self-Managed overview for a user who is not an admin: the instance can start a trial

Videos:

S1.1b before

S1.1b after

S2.2b before

S2.2b after

M3.2 before

M3.2 after

Texts that were not true for the state

Self-Managed, as the administrator. Before: the base of this MR (64bfbd5d, !263732 (merged)). After: 40968abd. The admin card states that the local CustomersDot cannot make are rewritten in the browser; the page code is real.

Item	Before	After
A1: Query editor, administrator, the instance can start a trial
A1: Query editor, administrator, the instance needs a purchase
A2: Admin card, the trial credits are used up before the end date (access answer rewritten in the browser)
C2: Admin health card, components with metadata (status answer rewritten in the browser)
C3: Admin card, no license for GitLab Orbit (access answer rewritten in the browser)

Videos:

A1, the instance can start a trial: before

A1, the instance can start a trial: after

A1, the instance needs a purchase: before

A1, the instance needs a purchase: after

No visible change: A3 and C5 are messages that the UI almost never shows, A4 is a polling interval, and C6 is the same "Cancel" text. The specs cover them.

How to set up and validate locally

Run the E2E catalog in https://gitlab.com/gitlab-org/orbit/knowledge-graph/-/work_items/1399. All Orbit Jest specs (1359) and the changed RSpec files pass.