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).

test/envsitter-guard.tools.test.ts

@@ -125,13 +125,14 @@ async function getTools(params: { directory: string; worktree: string }): Promis
         project: {} as unknown as PluginInput["project"],
         directory: params.directory,
         worktree: params.worktree,
+        experimental_workspace: { register() {} },
         serverUrl: new URL("http://localhost"),
         $: (() => {
             throw new Error("not used in tests");
         }) as unknown as PluginInput["$"],
     };
 
-    const hooks = (await EnvSitterGuard(pluginInput)) as unknown as {
+    const hooks = (await EnvSitterGuard.server(pluginInput)) as unknown as {
         tool: ToolApi;
     };
 
@@ -305,6 +306,24 @@ test("tool execution rejects paths outside worktree", async () => {
     );
 });
 
+test("envsitter tools accept named env files such as api.env", async () => {
+    await withPepper(async () => {
+        const worktree = await createTmpDir();
+        await fs.writeFile(path.join(worktree, "api.env"), "API_TOKEN=secret-token\n");
+
+        const tools = await getTools({ directory: worktree, worktree });
+        const out = await tools.envsitter_keys.execute({ filePath: "api.env" });
+
+        assert.ok(!out.includes("secret-token"));
+        assert.deepEqual((JSON.parse(out) as { keys: string[] }).keys, ["API_TOKEN"]);
+
+        await assert.rejects(
+            () => tools.envsitter_keys.execute({ filePath: "src/index.ts" }),
+            (err: unknown) => err instanceof Error && err.message.includes("Only dotenv files are allowed"),
+        );
+    });
+});
+
 test("tool execution blocks .envsitter/pepper", async () => {
     const worktree = await createTmpDir();
     const tools = await getTools({ directory: worktree, worktree });