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

skills/community/picoclaw/weather/SKILL.md

@@ -0,0 +1,49 @@
+---
+name: weather
+description: Get current weather and forecasts (no API key required).
+homepage: https://wttr.in/:help
+metadata: {"nanobot":{"emoji":"🌤️","requires":{"bins":["curl"]}}}
+---
+
+# Weather
+
+Two free services, no API keys needed.
+
+## wttr.in (primary)
+
+Quick one-liner:
+```bash
+curl -s "wttr.in/London?format=3"
+# Output: London: ⛅️ +8°C
+```
+
+Compact format:
+```bash
+curl -s "wttr.in/London?format=%l:+%c+%t+%h+%w"
+# Output: London: ⛅️ +8°C 71% ↙5km/h
+```
+
+Full forecast:
+```bash
+curl -s "wttr.in/London?T"
+```
+
+Format codes: `%c` condition · `%t` temp · `%h` humidity · `%w` wind · `%l` location · `%m` moon
+
+Tips:
+- URL-encode spaces: `wttr.in/New+York`
+- Airport codes: `wttr.in/JFK`
+- Units: `?m` (metric) `?u` (USCS)
+- Today only: `?1` · Current only: `?0`
+- PNG: `curl -s "wttr.in/Berlin.png" -o /tmp/weather.png`
+
+## Open-Meteo (fallback, JSON)
+
+Free, no key, good for programmatic use:
+```bash
+curl -s "https://api.open-meteo.com/v1/forecast?latitude=51.5&longitude=-0.12&current_weather=true"
+```
+
+Find coordinates for a city, then query. Returns JSON with temp, windspeed, weathercode.
+
+Docs: https://open-meteo.com/en/docs