fix: add cmux __tmux-compat prefix to interactive_bash tool

Extract isCmuxCompatEnvironment to shared module and fix
interactive_bash to resolve cmux executables with the __tmux-compat
prefix, matching all other tmux command paths in the codebase.

src/tools/interactive-bash/tmux-path-resolver.ts

@@ -1,14 +1,10 @@
 import { spawn } from "../../shared/bun-spawn-shim"
+import { isCmuxCompatEnvironment } from "../../shared/tmux/cmux-detect"
 
 let tmuxPath: string | null = null
 let initPromise: Promise<string | null> | null = null
 let tmuxPathEnvironmentKey: "cmux" | "tmux" | null = null
 
-function isCmuxCompatEnvironment(): boolean {
-  return Boolean(process.env.CMUX_SOCKET_PATH) ||
-    process.env.TMUX?.includes("cmuxterm") === true
-}
-
 function getEnvironmentKey(): "cmux" | "tmux" {
   return isCmuxCompatEnvironment() ? "cmux" : "tmux"
 }

src/tools/interactive-bash/tools.ts

@@ -1,8 +1,19 @@
 import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
 import { spawnWithWindowsHide } from "../../shared/spawn-with-windows-hide"
+import { isCmuxCompatEnvironment } from "../../shared/tmux/cmux-detect"
 import { BLOCKED_TMUX_SUBCOMMANDS, DEFAULT_TIMEOUT_MS, INTERACTIVE_BASH_DESCRIPTION } from "./constants"
 import { getCachedTmuxPath } from "./tmux-path-resolver"
 
+function resolveTmuxExecutable(tmuxPath: string): string[] {
+  if (!isCmuxCompatEnvironment()) {
+    return [tmuxPath]
+  }
+
+  const executableName = tmuxPath.split(/[\\/]/).pop()
+  const cmuxExecutable = executableName === "cmux" ? tmuxPath : "cmux"
+  return [cmuxExecutable, "__tmux-compat"]
+}
+
 /**
  * Quote-aware command tokenizer with escape handling
  * Handles single/double quotes and backslash escapes without external dependencies
@@ -90,7 +101,7 @@ tmux capture-pane -p -t ${sessionName} -S -1000
 The Bash tool can execute these commands directly. Do NOT retry with interactive_bash.`
       }
 
-      const proc = spawnWithWindowsHide([tmuxPath, ...parts], {
+      const proc = spawnWithWindowsHide([...resolveTmuxExecutable(tmuxPath), ...parts], {
         stdout: "pipe",
         stderr: "pipe",
       })