Confluence connector

[fuseraft]

Implement the Confluence connector described in docs/features/connectors.md under "Planned Connectors" — part of the Short Term (v0.2–0.3) roadmap.

Planned scope (from docs):

• Space and page hierarchy traversal
• Attachments extraction
• Labels → tags mapping
• Page relationships preservation
• Version history tracking

Target CLI surface:

compendium connect confluence \
  --space "EA" \
  --url https://company.atlassian.net \
  --bundle my-catalog \
  --type Document \
  --token $CONFLUENCE_TOKEN

Depends on the connector plugin architecture issue (IConnector + ConnectorRegistry).