PR #16369 - onyx-dot-app/onyx

Description

Part 4 of the ENG-4416 stack. Chat Preferences > Connectors showed only the first 3 sources and gave no context. It now:

lists every connected source and wraps,
explains "Sources that Internal Search uses in chat. Add or change them on the indexing status page.",
labels the link "Manage connectors".

Before (desktop)	After (desktop)	Before (mobile)	After (mobile)

How Has This Been Tested?

Local ODS stack with 7 connector sources: before, 3 of 7 showed; after, all 7 show on desktop and mobile.
New jest test lists every connector source and explains the section; ChatPreferencesPage suite passes.
pre-commit on touched files.

Additional Options

[Optional] Please cherry-pick this PR to the latest release version.

Link to Devin session: https://app.devin.ai/sessions/09df74c24e19407bbf0e7ab775b5cb0a
Open in Devin Desktop: https://app.devin.ai/desktop/session/09df74c24e19407bbf0e7ab775b5cb0a?variant=devin
Requested by: @rohoswagger

Summary by cubic

Makes Chat Preferences list every connector source instead of showing only the first three, explains what the section is for, and stacks the header on narrow screens. The management link is now labeled "Manage connectors", only shows when sources exist, and points to the indexing status page. Tests cover the full list, description, and link behavior. Part of the ENG-4416 UX cleanup.

Summary by CodeRabbit

New Features
- Chat preferences now display all available connector sources.
- Added guidance explaining that connectors power Internal Search and are managed from the indexing status page.
- Updated the management link label to “Manage connectors” and linked it to the indexing status page.
- The management link remains hidden when no connectors are available; the empty state is unchanged.
- Updated connector-related text across supported languages.
Tests
- Added coverage for connector listings, guidance, and management navigation.