Feature Request: Add Factory Droids support

[lukeaus]

Problem

Factory Droids (https://factory.ai) is a coding agent platform that supports plugins with skills, MCP servers, and lifecycle hooks — the same three primitives agentmemory already uses for its Claude Code and Codex CLI integrations. Currently, there is no plugin manifest or hooks config for Factory Droids, so Droid users can only use agentmemory via the generic MCP server config and miss out on automatic session tracking, memory capture, and skill commands.

Proposed solution

Add a Factory Droids plugin that mirrors the existing first-class Claude Code support (12 hooks + MCP + 4 skills), consisting of:

1. plugin/.factory-plugin/plugin.json — Factory plugin manifest wiring hooks, skills, and MCP
2. plugin/hooks/hooks.factory.json — 12 lifecycle hooks using FACTORY_PLUGIN_ROOT
3. .factory-plugin/marketplace.json — Marketplace discovery manifest for droid plugin install
4. Documentation updates — README, CONTRIBUTING.md, SECURITY.md

All 12 hooks share the same plugin/scripts/*.mjs files as Claude Code and Codex — only the env variable differs (FACTORY_PLUGIN_ROOT vs CLAUDE_PLUGIN_ROOT), so no new script files are needed.

Why this is valuable

• 12 hooks gives Droid users full parity with Claude Code (session tracking, tool capture, memory consolidation on stop/session-end, subagent tracking, notification handling)
• droid plugin install agentmemory one-command setup instead of manual MCP config
• 4 skills (/recall, /remember, /session-history, /forget) work out of the box
• Shared memory server — Droid sessions join the same memory graph as Claude Code, Codex, Cursor, etc.

PR

Implemented in #329