feat(plugin): add shell.env hook for manipulating environment in tools and shell (#12012)

packages/opencode/src/session/prompt.ts

@@ -1500,12 +1500,15 @@ NOTE: At any point in time through this workflow you should feel free to ask the
     const matchingInvocation = invocations[shellName] ?? invocations[""]
     const args = matchingInvocation?.args
 
+    const cwd = Instance.directory
+    const shellEnv = await Plugin.trigger("shell.env", { cwd }, { env: {} })
     const proc = spawn(shell, args, {
-      cwd: Instance.directory,
+      cwd,
       detached: process.platform !== "win32",
       stdio: ["ignore", "pipe", "pipe"],
       env: {
         ...process.env,
+        ...shellEnv.env,
         TERM: "dumb",
       },
     })