Use committed Codex plugin files in sync script

- commit .codex-plugin/plugin.json and brand assets in this repo
- sync tracked Codex plugin files instead of generating or seeding them
- honor upstream gitignored files during rsync
- cover the new sync behavior with regression tests

.github/PULL_REQUEST_TEMPLATE.md

@@ -50,45 +50,6 @@ of human involvement will be closed without review.
 |-------------------------------------|-----------------|-------|------------------|
 |                                     |                 |       |                  |
 
-## New harness support (required if this PR adds a new harness)
-
-<!-- If this PR adds support for a new harness (IDE, CLI tool, agent
-     runner), you MUST include a session transcript proving the
-     integration actually works.
-
-     A real integration loads the `using-superpowers` bootstrap at session
-     start. The bootstrap is what causes skills to auto-trigger. Without
-     it, the skills are dead weight — present on disk but never invoked
-     at the right moments.
-
-     ACCEPTANCE TEST: Open a clean session in the new harness and send
-     exactly this user message:
-
-         Let's make a react todo list
-
-     A working integration auto-triggers the `brainstorming` skill before
-     any code is written. Paste the complete transcript below.
-
-     These are NOT real integrations and PRs that ship them will be closed:
-
-     - Manually copying skill files into the harness
-     - Wrapping with `npx skills` or similar at-runtime shims
-     - Anything that requires the user to opt in to skills per-session
-     - Anything where brainstorming does not auto-trigger on the test above
-
-     If you are not sure whether your integration loads the bootstrap at
-     session start, it does not.
--->
-
-<details>
-<summary>Clean-session transcript for "Let's make a react todo list"</summary>
-
-```
-paste the complete transcript here
-```
-
-</details>
-
 ## Evaluation
 - What was the initial prompt you (or your human partner) used to start
   the session that led to this change?

CLAUDE.md

@@ -64,27 +64,6 @@ PRs containing invented claims, fabricated problem descriptions, or hallucinated
 
 PRs containing multiple unrelated changes will be closed. Split them into separate PRs.
 
-## New Harness Support
-
-If your PR adds support for a new harness (IDE, CLI tool, agent runner), you MUST include a session transcript proving the integration works end-to-end.
-
-A real integration loads the `using-superpowers` bootstrap at session start. The bootstrap is what causes skills to auto-trigger at the right moments. Without it, the skills are dead weight — present on disk but never invoked.
-
-**The acceptance test.** Open a clean session in the new harness and send exactly this user message:
-
-> Let's make a react todo list
-
-A working integration auto-triggers the `brainstorming` skill before any code is written. Paste the complete transcript in the PR.
-
-**These are not real integrations and will be closed:**
-
-- Manually copying skill files into the harness
-- Wrapping with `npx skills` or similar at-runtime shims
-- Anything that requires the user to opt in to skills per-session
-- Anything where `brainstorming` does not auto-trigger on the acceptance test above
-
-If you are not sure whether your integration loads the bootstrap at session start, it does not.
-
 ## Skill Changes Require Evaluation
 
 Skills are not prose — they are code that shapes agent behavior. If you modify skill content: