fix: update opencode-ecc plugin for SDK v1.1.53 and refresh README stats

- Fix PluginContext → PluginInput type rename in @opencode-ai/plugin
- Import tool from @opencode-ai/plugin/tool subpath (fixes broken barrel export)
- Update client.app.log() calls to use new options-object API signature
- Stringify tool execute return values (SDK now requires Promise<string>)
- Add .js extensions to relative imports for NodeNext module resolution
- Update README star count (42K+) and contributor count (24)

.opencode/tools/security-audit.ts

@@ -8,7 +8,7 @@
  * The regex patterns below are used to DETECT potential issues in user code.
  */
 
-import { tool } from "@opencode-ai/plugin"
+import { tool } from "@opencode-ai/plugin/tool"
 import * as path from "path"
 import * as fs from "fs"
 
@@ -102,7 +102,7 @@ export default tool({
     // Generate recommendations
     results.recommendations = generateRecommendations(results)
 
-    return results
+    return JSON.stringify(results)
   },
 })