Add recsys-pipeline-architect (Development & Code Tools)

[mturac]

Adds recsys-pipeline-architect under Development & Code Tools.

What it is
A skill for designing composable recommendation, ranking, and feed pipelines using the six-stage Source → Hydrator → Filter → Scorer → Selector → SideEffect framework popularized by xAI's open-sourced For You algorithm (Apache 2.0 pattern; this skill is MIT and is an independent reimplementation).

Why it fits
Most "recommendation systems" in production aren't exotic ML — they're pipelines. This skill encodes that pattern, walks Claude through eight clarifying steps (use case → sources → hydrations → filters → scorers → selector → side effects → scaffold), surfaces architectural trade-offs (multi-action vs single-score, candidate isolation vs joint, online vs offline), and emits a runnable scaffold in the user's stack.

What's in the repo

• SKILL.md (the skill itself, ~14KB) + 5 load-on-demand reference docs
• 3 runnable example scaffolds, every one green on its test suite:
  • Strapi v5 plugin (TypeScript, Jest — 3/3 pass)
  • Zentra-compatible pipeline (Go with generics — 3/3 pass)
  • PMAI task prioritizer (Python / FastAPI — 3/3 pass)
• MIT license, attribution to the X For You pattern in README + LICENSE
• v0.1.0 GitHub release with install instructions

Inserted alphabetically between pypict-claude-skill and reddit-fetch. Description kept to one line in the style of other entries; author byline at the end.

Happy to revise the description, move to a different category, or shorten further — just let me know.