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

agents/community/toad/vibe.mistral.ai.toml

@@ -0,0 +1,27 @@
+# Schema defined in agent_schema.py
+# https://www.claude.com/product/claude-code
+
+identity = "vibe.mistral.ai"
+name = "Mistral Vibe"
+short_name = "vibe"
+url = "https://mistral.ai/news/devstral-2-vibe-cli"
+protocol = "acp"
+author_name = "Mistral"
+author_url = "https://mistral.ai/"
+publisher_name = "Will McGugan"
+publisher_url = "https://willmcgugan.github.io/"
+type = "coding"
+description = "State-of-the-art, open-source agentic coding models and CLI agent."
+tags = []
+run_command."*" = "vibe-acp"
+
+help = '''
+# Devstral2 Mistral Vibe CLI
+
+Today, we're releasing Devstral 2—our next-generation coding model family available in two sizes: Devstral 2 (123B) and Devstral Small 2 (24B). Devstral 2 ships under a modified MIT license, while Devstral Small 2 uses Apache 2.0. Both are open-source and permissively licensed to accelerate distributed intelligence.
+'''
+
+
+[actions."*".install]
+command = "curl -LsSf https://mistral.ai/vibe/install.sh | bash"
+description = "Install Mistral Vibe"