Require contributors to disclose authoring environment and target dev

Add a mandatory self-identification disclosure (model, harness, harness
version, all installed plugins) to the PR template and all three issue
templates, and document the requirement in the contributor guidelines.
We weigh contributions differently depending on what produced them:
content reasoned from documentation is held to a different bar than work
grounded in a real session.

Also state explicitly, in both CLAUDE.md and the PR template, that all
PRs must target the dev branch rather than main.

README.md

@@ -2,13 +2,6 @@
 
 Superpowers is a complete software development methodology for your coding agents, built on top of a set of composable skills and some initial instructions that make sure your agent uses them.
 
-
-## We're Hiring!
-
-We're hiring someone to help out full time with Superpowers community and code work. 
-You can read about the job at https://primeradiant.com/jobs/superpowers-community-engineer/
-If this sounds like someone you know, definitely send them our way.
-
 ## Quickstart
 
 Give your agent Superpowers: [Claude Code](#claude-code), [Codex CLI](#codex-cli), [Codex App](#codex-app), [Factory Droid](#factory-droid), [Gemini CLI](#gemini-cli), [OpenCode](#opencode), [Cursor](#cursor), [GitHub Copilot CLI](#github-copilot-cli).