feat: support OpenCode 2 and scrub secret values from tool output

- Default export is { id, setup, server }: OpenCode 2 calls setup(ctx), OpenCode 1 (1.18.29+) calls server()
- Tools defined once in lib/tools.ts and registered for both versions (V2 with codemode: false)
- Blocking covers path args of any tool, patch/apply_patch envelopes, shell commands naming env files, grep output, and V2 permission checks
- Secret-looking values from the project's env files are replaced in every non-envsitter tool's output
- Protected files come from envsitter's path policy; example/template files stay readable
- npm run test:e2e drives the real OpenCode 1 and 2 CLIs with a scripted model
- @opencode-ai/plugin ^1.19.3, @opencode/plugin ^2.1.0 (peer >=2.0.32), envsitter ^0.1.0, TypeScript 6

BREAKING CHANGE: the named export EnvSitterGuard is now the plugin definition object; call EnvSitterGuard.server(input) instead of EnvSitterGuard(input).

tsconfig.json

@@ -8,5 +8,5 @@
     "types": ["node"],
     "skipLibCheck": true
   },
-  "include": ["index.ts", ".opencode/plugin/**/*.ts"]
+  "include": ["index.ts", ".opencode/plugin/**/*.ts", "test/**/*.ts"]
 }