fix: correct Claude Code plugin structure for marketplace

- Move plugin.json to .claude-plugin/plugin.json with correct format
  (author as object, removed unrecognized claudeCode/skills/hooks fields)
- Add .claude-plugin/marketplace.json for plugin marketplace discovery
- Add YAML frontmatter to skills/prism-analyze/SKILL.md
- Fix README install command: /plugin install prism@prism
- Delete root-level plugin.json

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jakeefr

.claude-plugin/marketplace.json

@@ -0,0 +1,12 @@
+{
+  "name": "prism",
+  "owner": { "name": "jakeefr" },
+  "plugins": [
+    {
+      "name": "prism",
+      "source": { "source": "github", "repo": "jakeefr/prism" },
+      "description": "Session intelligence for Claude Code — find why your sessions fail and fix them",
+      "version": "0.2.0"
+    }
+  ]
+}

.claude-plugin/plugin.json

@@ -0,0 +1,8 @@
+{
+  "name": "prism",
+  "description": "Session intelligence for Claude Code — find why your sessions fail and fix them",
+  "version": "0.2.0",
+  "author": { "name": "jakeefr" },
+  "license": "MIT",
+  "repository": "https://github.com/jakeefr/prism"
+}

README.md

@@ -236,7 +236,7 @@ pipx install prism-cc
 
 # Claude Code plugin
 /plugin marketplace add jakeefr/prism
-/plugin install prism
+/plugin install prism@prism
 
 # from source
 git clone https://github.com/jakeefr/prism

plugin.json

@@ -1,3 +1,7 @@
+---
+description: Analyze Claude Code session health using PRISM. Use when asked to check token usage, audit CLAUDE.md, or understand why sessions are failing.
+---
+
 # prism-analyze
 
 Analyze Claude Code session health using PRISM.