Remove broken autofix-bot marketplace entry

The autofix-bot entry points to ./external_plugins/autofix-bot which has
never existed in this repository. The entry was added in #677 (staging
merge) but the plugin directory was not included — likely copied from
claude-plugins-public without bringing over the files.

.claude-plugin/marketplace.json

@@ -125,16 +125,6 @@
         "community-managed"
       ]
     },
-    {
-      "name": "autofix-bot",
-      "description": "Code review agent that detects security vulnerabilities, code quality issues, and hardcoded secrets. Combines 5,000+ static analyzers to scan your code and dependencies for CVEs.",
-      "author": {
-        "name": "DeepSource Corp"
-      },
-      "category": "security",
-      "source": "./external_plugins/autofix-bot",
-      "homepage": "https://github.com/anthropics/claude-plugins-public/tree/main/external_plugins/autofix-bot"
-    },
     {
       "name": "aws-serverless",
       "description": "Design, build, deploy, test, and debug serverless applications with AWS Serverless services.",
@@ -694,17 +684,6 @@
         }
       }
     },
-    {
-      "name": "math-olympiad",
-      "description": "Solve competition math (IMO, Putnam, USAMO) with adversarial verification that catches what self-verification misses. Fresh-context verifiers attack proofs with specific failure patterns. Calibrated abstention over bluffing.",
-      "author": {
-        "name": "Anthropic",
-        "email": "support@anthropic.com"
-      },
-      "source": "./plugins/math-olympiad",
-      "category": "productivity",
-      "homepage": "https://github.com/anthropics/claude-plugins-official/tree/main/plugins/math-olympiad"
-    },
     {
       "name": "mcp-server-dev",
       "description": "Skills for designing and building MCP servers that work seamlessly with Claude. Guides you through deployment models (remote HTTP, MCPB, local), tool design patterns, auth, and interactive MCP apps.",

external_plugins/terraform/.claude-plugin/plugin.json

@@ -0,0 +1,7 @@
+{
+  "name": "terraform",
+  "description": "The Terraform MCP Server provides seamless integration with Terraform ecosystem, enabling advanced automation and interaction capabilities for Infrastructure as Code (IaC) development.",
+  "author": {
+    "name": "HashiCorp"
+  }
+}

external_plugins/terraform/.mcp.json

@@ -0,0 +1,12 @@
+{
+  "terraform": {
+    "command": "docker",
+    "args": [
+      "run",
+      "-i",
+      "--rm",
+      "-e", "TFE_TOKEN=${TFE_TOKEN}",
+      "hashicorp/terraform-mcp-server:0.4.0"
+    ]
+  }
+}