docs(catalog): bring the catalog up to the repo-standard gate

Ran repo-standard v0.1.1 against this repo (class `catalog`): 5 ERROR, 4 WARN.
Three ERRORs were real and are fixed here:

- LICENSE was missing while README and GOVERNANCE both claim MIT — the claim a
  reader relies on was unbacked. Adds the same MIT text the plugin repos carry.
- `## Installation` -> `## Install`. The contract wants the fixed heading
  because that is what an agent pattern-matches on; the block itself was already
  the catalog form (`marketplace add` only, https, no plugin install line).
- Adds `## Non-goals`, grounded in GOVERNANCE.md: source and issues live in each
  plugin repo, no third-party submissions, no PRs, no support commitment.

README's opening line also carried a trailing period that neither the forge
description nor `marketplace.json:metadata.description` has. The README was the
odd one out of three, so it loses the period — description == catalog == README
is the only place a machine can check the three agree.

The two remaining ERRORs are a gate defect, not a repo defect, and are
deliberately NOT silenced. `RUNBOOK.md:39` and `:114` contain
`https://.../api/v1/orgs/open/repos` — the Forgejo endpoint for creating an org
repo. The checker's `URL_REF` regex reads the `repos` collection segment as a
repo name. Measured: `GET /api/v1/orgs/open/repos` -> HTTP 200 (live API),
`GET /open/repos` -> HTTP 404 (no such repo), and repo-standard-check.mjs:705
builds the identical URL, so the gate would flag itself. The runbook text is
correct and stays; the classifier fix belongs in the repo-standard repo and has
been routed there.

The 4 WARNs (LINK-INTERNAL-MISSING) all stand by design: they are inside
`test/nav-golden-corpus/`, where `bundle/index.md`'s escaping links ARE the
traversal test, and `expected-read-context.md` is expected OUTPUT text whose
links are data, not navigation. Repairing any of them would delete the test.

Gate after: 10 checks pass, 0 real ERROR. check-versions 12 OK/0 ERROR,
tests 120/120.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H4zqeGKBfAA2r8buPVefNR

README.md

@@ -1,12 +1,12 @@
 # ktg-plugin-marketplace
 
-Open-source Claude Code plugins for AI-assisted development, security, and planning.
+Open-source Claude Code plugins for AI-assisted development, security, and planning
 
 Built for my own Claude Code workflow and shared openly for anyone who finds them useful. Solo-maintained, AI-assisted, fork-and-own. Issues are welcome as signals; pull requests are not accepted. See [GOVERNANCE.md](GOVERNANCE.md) for what upstream provides and how this is meant to be used.
 
 All code here is generated by Claude Code through a dialog-based process: I direct, review, test, and validate; Claude writes. Treat the plugins as AI-authored, human-curated.
 
-## Installation
+## Install
 
 ```bash
 claude plugin marketplace add https://git.fromaitochitta.com/open/ktg-plugin-marketplace.git
@@ -16,6 +16,13 @@ Then open Claude Code and type `/plugin` to browse and install — the command a
 
 Each plugin keeps its own full README and CHANGELOG; this page is just the catalog.
 
+## Non-goals
+
+- **Not a host for plugin source or issues.** This repository holds the marketplace manifest and this catalog page. Code, issues and releases live in each plugin's own repository, linked from its entry below.
+- **Not a third-party registry.** Only plugins maintained here are listed. There is no submission process.
+- **No pull requests.** Issues are welcome as signals; PRs are not accepted. See [GOVERNANCE.md](GOVERNANCE.md) for the reasoning and the fork-and-own model.
+- **No support commitment.** Bug fixes are best-effort, breaking changes happen and are documented in each plugin's CHANGELOG. Version-pin if you need stability.
+
 ---
 
 ## Plugins