One vocabulary: Knowledge, tools, and connectors in plain words

- Sources (the collection) are called Knowledge: the settings page (now
  /settings/knowledge; /settings/sources redirects), the composer and
  agent pickers, Add knowledge, and "syncs into Knowledge" on connectors.
  Citations keep "sources". All seven locales.
- Connector cards describe what they do ("Syncs into Knowledge", "Looks
  things up", "Takes actions") and drop publisher labels ("Built in",
  "Preset"). Filters read "Files & storage" and "Docs & wikis" so
  "knowledge" means one thing.
- Custom tools are tools: "Add custom tool". The agent picker no longer
  splits built-in tools into "Built-in" and "Default".
- Confluence is one card: syncing pages into Knowledge and the Jira &
  Confluence MCP actions (part_of on the preset) share a page. The part
  shows on its own when Confluence sync is not set up.

docs/content/Guides/Connectors.mdx

@@ -1,6 +1,6 @@
 ---
 title: Connectors
-description: Connect DocsGPT to the services your team uses. One connection can sync content into Sources and give agents tools, with credentials encrypted on the server.
+description: Connect DocsGPT to the services your team uses. One connection can sync content into Knowledge and give agents tools, with credentials encrypted on the server.
 ---
 
 import { Callout } from 'nextra/components'
@@ -20,7 +20,7 @@ Open **Settings > Connectors**. Filters narrow the list by category, and **Conne
 2. Choose what the connection sets up. File services offer a synced source (pick files or folders, then how often to sync: never, daily, weekly or monthly). Tool services create their tools right away.
 3. Adjust what the tools may do. Each action is **Read** or **Write**, and each can be **Always allow**, **Needs approval** or **Off**. Writes default to needing approval.
 
-The **Add Source** and **Add Tool** dialogs, the composer's Sources and Tools menus, and the agent builder all start the same flow, and list tools grouped by the connection they use.
+**Knowledge** (formerly Sources) is what the assistant searches: uploads, links, and content synced from your connections. The **Add knowledge** and **Add Tool** dialogs, the composer's Knowledge and Tools menus, and the agent builder all start the same flow, and list tools grouped by the connection they use. A service offered two ways appears as one card: Confluence syncs pages into Knowledge and, through **Jira & Confluence**, lets agents search and update Jira and Confluence.
 
 Click a connected card to see its account, the sources and tools that use it, and to **Reconnect** or **Disconnect**. Disconnecting keeps a source's indexed content but stops its sync.