feat(team-mode): add core types, dependencies and type-level tests

src/features/team-mode/deps.ts

@@ -0,0 +1,29 @@
+import type { TeamModeConfig } from "../../config/schema/team-mode"
+
+export interface TeamModeDependencyReport {
+  tmuxAvailable: boolean
+  gitAvailable: boolean
+}
+
+export async function checkTeamModeDependencies(
+  config: TeamModeConfig,
+): Promise<TeamModeDependencyReport> {
+  const tmuxAvailable = Boolean(process.env["TMUX"]) || (await probeBinary("tmux", ["-V"]))
+  const gitAvailable = await probeBinary("git", ["--version"])
+  if (config.tmux_visualization && !tmuxAvailable) {
+    console.warn(
+      "[team-mode] tmux_visualization=true but tmux not available; layout will be skipped at runtime",
+    )
+  }
+  return { tmuxAvailable, gitAvailable }
+}
+
+async function probeBinary(cmd: string, args: string[]): Promise<boolean> {
+  try {
+    const proc = Bun.spawn({ cmd: [cmd, ...args], stdout: "pipe", stderr: "pipe" })
+    const code = await proc.exited
+    return code === 0
+  } catch {
+    return false
+  }
+}