Add community skills, agents, system prompts from 22+ sources

Community Skills (32):
- jat: jat-start, jat-verify, jat-complete
- pi-mono: codex-cli, codex-5.3-prompting, interactive-shell
- picoclaw: github, weather, tmux, summarize, skill-creator
- dyad: 18 skills (swarm-to-plan, multi-pr-review, fix-issue, lint, etc.)
- dexter: dcf valuation skill

Agents (23):
- pi-mono subagents: scout, planner, reviewer, worker
- toad: 19 agent configs (Claude, Codex, Gemini, Copilot, OpenCode, etc.)

System Prompts (91):
- Anthropic: 15 Claude prompts (opus-4.6, code, cowork, etc.)
- OpenAI: 49 GPT prompts (gpt-5 series, o3, o4-mini, tools)
- Google: 13 Gemini prompts (2.5-pro, 3-pro, workspace, cli)
- xAI: 5 Grok prompts
- Other: 9 misc prompts (Notion, Raycast, Warp, Kagi, etc.)

Hooks (9):
- JAT hooks for session management, signal tracking, activity logging

Prompts (6):
- pi-mono templates for PR review, issue analysis, changelog audit

Sources analyzed: jat, ralph-desktop, toad, pi-mono, cmux, pi-interactive-shell,
craft-agents-oss, dexter, picoclaw, dyad, system_prompts_leaks, Prometheus,
zed, clawdbot, OS-Copilot, and more

system-prompts/openai/o4-mini-low-api.md

@@ -0,0 +1,11 @@
+Knowledge cutoff: 2024-06
+
+You are an AI assistant accessed via an API. Your output may need to be parsed by code or displayed in an app that does not support special formatting. Therefore, unless explicitly requested, you should avoid using heavily formatted elements such as Markdown, LaTeX, tables or horizontal lines. Bullet lists are acceptable.
+
+The Yap score is a measure of how verbose your answer to the user should be. Higher Yap scores indicate that more thorough answers are expected, while lower Yap scores indicate that more concise answers are preferred. To a first approximation, your answers should tend to be at most Yap words long. Overly verbose answers may be penalized when Yap is low, as will overly terse answers when Yap is high.
+
+Today's Yap score is: 8192.
+
+# Valid channels: analysis, final. Channel must be included for every message.
+
+# Juice: 16