Feature: Factory Droid adapter (plugin + hooks + portability doc)

[Duy-Nguyen-2006]

Summary

Add a Factory Droid adapter so ponytail works with the same depth as the Claude Code / Codex plugins: always-on rules, intensity levels (lite / full / ultra / off), and the five skills as slash commands.

There is no existing issue or PR for Droid/Factory in this repo. docs/agent-portability.md lists 13+ hosts but not Factory Droid.

Why Droid is a good fit

Factory Droid already supports the same building blocks ponytail uses elsewhere:

Ponytail piece	Droid equivalent
skills/*/SKILL.md	~/.factory/skills/ or .factory/skills/ (skills)
AGENTS.md	Auto-discovered at repo root / ~/.factory/AGENTS.md (AGENTS.md)
SessionStart + UserPromptSubmit hooks	Same event names (hooks reference)
Claude plugin layout	Droid is Claude Code plugin compatible; plugins use ${DROID_PLUGIN_ROOT} instead of ${CLAUDE_PLUGIN_ROOT}

Droid’s UserPromptSubmit / SessionStart hooks can inject additionalContext via JSON stdout—the same pattern Codex uses in hooks/ponytail-runtime.js.

Proposed adapter (keep adapters thin)

Per docs/agent-portability.md, point the host at existing assets:

1. .factory-plugin/plugin.json (manifest; mirror .claude-plugin/plugin.json fields).
2. hooks/hooks.json (or hooks/factory-hooks.json if root hooks.json must stay host-specific—see Gemini CLI: Invalid hook event name 'UserPromptSubmit' warning #137 / PR Avoid Gemini loading Claude hook events #139 pattern for Gemini vs Claude/Codex).
   • SessionStart → node "${DROID_PLUGIN_ROOT}/hooks/ponytail-activate.js"
   • UserPromptSubmit → node "${DROID_PLUGIN_ROOT}/hooks/ponytail-mode-tracker.js"
3. skills/ — unchanged (plugin bundles or references repo skills/).
4. commands/ — optional slash prompts for /ponytail, /ponytail-review, etc. (Droid merges commands into skills slash namespace).
5. docs/agent-portability.md — new row: Factory Droid | .factory-plugin/, skills/, hooks/, AGENTS.md | Plugin install + hooks; instruction-only fallback via AGENTS.md + skills copy.

Code changes likely needed (small)

• hooks/ponytail-runtime.js: detect DROID_PLUGIN_ROOT (and/or Factory-specific env) for state path + writeHookOutput JSON shape for Droid (same as Codex hookSpecificOutput on SessionStart / UserPromptSubmit).
• hooks/ponytail-config.js: state file location — today ~/.claude/.ponytail-active; consider ~/.factory/.ponytail-active when running under Droid (or host-agnostic getStateDir()).
• Deactivation fix (Ponytail silently turns off when a prompt happens to contain "normal mode" #161 / PR fix: only deactivate ponytail on a standalone stop command #162): when touching ponytail-mode-tracker.js, use standalone isDeactivationCommand so prompts like “add a normal mode toggle” do not silently disable ponytail on Droid too.

Install UX (document in README)

droid plugin marketplace add https://github.com/DietrichGebert/ponytail
droid plugin install ponytail@ponytail --scope user   # or project

Users must review/trust hooks in /hooks (same as Codex). Requires node on PATH for lifecycle hooks.

Instruction-only fallback (no hooks): copy AGENTS.md + skills/ into project or ~/.factory/ — same as Generic agents row, without lite/full/ultra persistence.

Acceptance criteria

• Plugin installs via droid plugin from this repo’s marketplace manifest.
• New session injects ponytail rules at default mode (full unless PONYTAIL_DEFAULT_MODE / config).
• /ponytail lite|full|ultra|off (or equivalent command) changes mode for the session.
• All five skills discoverable; /ponytail-review, /ponytail-audit, /ponytail-debt, /ponytail-help work.
• node scripts/check-rule-copies.js and existing hook tests still pass; add a manifest test for Factory hook paths if the repo already tests other hosts.
• docs/agent-portability.md updated; README install section mentions Droid.

References

• Upstream portability doc: docs/agent-portability.md
• Related host adapter work: OpenCode path independence (issues in repo), Gemini UserPromptSubmit (Gemini CLI: Invalid hook event name 'UserPromptSubmit' warning #137), Copilot CLI plugin namespace
• Factory docs index: https://docs.factory.ai/llms.txt

Happy to help test a PR on Linux with droid CLI if useful.