feat(skills): add promptfoo skill for LLM evaluation and red-teaming

Covers install, configuration, running evals, red-teaming, CI/CD
integration, and dataset generation. Pins to v0.121.17 with acquisition
notice (OpenAI, March 2026) and documented fallbacks (DeepEval, Arize Phoenix).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/kyberforge/skills/promptfoo/references/installation.md

@@ -0,0 +1,70 @@
+---
+topic: installation
+source_keys:
+  - context7-promptfoo-dev
+  - context7-promptfoo-github
+---
+
+## Acquisition notice
+
+Promptfoo was acquired by OpenAI in March 2026. OpenAI has committed to keeping it open-source and multi-provider. **Always pin to a specific version** — do not track `@latest`. Monitor for neutrality degradation in future releases, particularly for non-OpenAI provider evaluation. Documented fallbacks: DeepEval (pytest-native, Python teams) and Arize Phoenix (self-hosted, vendor-neutral).
+
+Pinned version in this skill: **0.121.17**. Update via CI when a new version has been validated.
+
+## Prerequisites
+
+- Node.js 18+ (Node 22 recommended for CI)
+- npm or npx
+
+No database or server process is required. Promptfoo stores evaluation results in a local SQLite cache.
+
+## Installation options
+
+**One-off via npx (no install required — preferred):**
+```bash
+npx promptfoo@0.121.17 eval
+```
+
+**Global install (pinned):**
+```bash
+npm install -g promptfoo@0.121.17
+```
+After a global install, use `promptfoo` directly without `npx`.
+
+**Project dependency (for Node.js API usage):**
+```bash
+npm install promptfoo@0.121.17
+```
+
+## Initialising a project
+
+```bash
+npx promptfoo@0.121.17 init
+```
+
+Creates a `promptfooconfig.yaml` scaffold in the current directory with example prompts, providers, and tests.
+
+To start from an official example:
+```bash
+npx promptfoo@0.121.17 init --example openai-mcp
+npx promptfoo@0.121.17 init --example openai-structured-output
+npx promptfoo@0.121.17 init --example openai-responses
+npx promptfoo@0.121.17 init --example openai-audio
+```
+
+## API keys
+
+Promptfoo reads provider credentials from environment variables. Set them before running evals:
+
+```bash
+export OPENAI_API_KEY=sk-...
+export ANTHROPIC_API_KEY=sk-ant-...
+```
+
+Other providers (Bedrock, Azure, Vertex) follow their own SDK credential conventions — see provider-specific docs.
+
+## Global timeout
+
+```bash
+export REQUEST_TIMEOUT_MS=600000  # 10 minutes default
+```