tui: enable password authentication for remote session attachment

Allow users to authenticate when attaching to a remote OpenCode session by supporting basic auth via a password flag or OPENCODE_SERVER_PASSWORD environment variable

packages/opencode/src/cli/cmd/tui/attach.ts

@@ -19,21 +19,34 @@ export const AttachCommand = cmd({
         alias: ["s"],
         type: "string",
         describe: "session id to continue",
+      })
+      .option("password", {
+        alias: ["p"],
+        type: "string",
+        describe: "basic auth password (defaults to OPENCODE_SERVER_PASSWORD)",
       }),
   handler: async (args) => {
-    let directory = args.dir
-    if (args.dir) {
+    const directory = (() => {
+      if (!args.dir) return undefined
       try {
         process.chdir(args.dir)
-        directory = process.cwd()
+        return process.cwd()
       } catch {
         // If the directory doesn't exist locally (remote attach), pass it through.
+        return args.dir
       }
-    }
+    })()
+    const headers = (() => {
+      const password = args.password ?? process.env.OPENCODE_SERVER_PASSWORD
+      if (!password) return undefined
+      const auth = `Basic ${Buffer.from(`opencode:${password}`).toString("base64")}`
+      return { Authorization: auth }
+    })()
     await tui({
       url: args.url,
       args: { sessionID: args.session },
       directory,
+      headers,
     })
   },
 })