Add social-media-manager subagent (Business & Product)

[publora-team]

Summary

Adds a new social-media-manager subagent to categories/08-business-product/. This fills a gap the catalog already references — content-marketer lists "Help social-media-manager on distribution" in its agent integrations, but no such agent existed until now.

The subagent covers platform strategy, content calendars, cross-platform scheduling/publishing, community management, and analytics — following the standard template structure (frontmatter, When invoked, checklists, Communication Protocol, Development Workflow phases, Integration with other agents).

Files changed (per CONTRIBUTING)

• New: categories/08-business-product/social-media-manager.md — the agent definition
• README.md — added the agent link in the Business & Product section (alphabetical order)
• categories/08-business-product/README.md — added the Available Subagents entry, Quick Selection Guide row, and Go-to-Market pattern
• categories/08-business-product/.claude-plugin/plugin.json — added the agent to agents[] and bumped version 1.0.3 → 1.0.4
• .claude-plugin/marketplace.json — synced the voltagent-biz plugin version to 1.0.4

Notes

• Publishing-automation section references Publora as one example of a multi-platform publishing API/MCP (mcp.publora.com) for agent-driven scheduling — presented as an option alongside general best practices, not a requirement.
• Both JSON files validate; category and marketplace versions are in sync.

[publora-team]

Hi! 👋 Friendly bump — this adds a social-media-manager subagent under Business & Product. Still clean and mergeable; happy to tweak the frontmatter or examples to match your conventions. Thanks!