Add pluginpool (10 productivity plugins)

[mturac]

Adds pluginpool to Claude Plugins.

A marketplace of ten focused Claude Code plugins for everyday developer productivity:

Plugin	What it does	Tests
commit-narrator	Semantic commit message from git diff --cached, including the why	8
pr-storyteller	PR title + body + test plan from commits and diff vs base branch	6
test-gap	Lines in your diff lacking test coverage (Cobertura / lcov / coverage.json)	9
deps-doctor	Multi-ecosystem dependency audit (npm, pip, cargo, go) — one report	8
env-lint	.env vs .env.example key parity — never prints values	7
secret-guard	Pre-commit secret scanner (pattern + entropy, redacted output)	10
standup-gen	Daily standup notes from git activity across one or many repos	8
todo-harvest	TODO/FIXME/HACK scan with git blame author + age	9
flaky-detector	Run a test command N times, report per-test flakiness %	11
changelog-forge	Conventional commits → CHANGELOG section + semver bump suggestion	13

89 hermetic tests across the suite. All green. Python stdlib only at runtime. MIT. Each plugin is its own repo; install one or install all. Or add as a marketplace: /plugin marketplace add mturac/pluginpool.