feat: cmux as configurable backend for session management

lua/agent-deck/backend.lua

@@ -0,0 +1,57 @@
+-- backend.lua — dispatch layer for backend abstraction
+--
+-- Single entry point for all backend operations. Callers use
+-- require("agent-deck.backend") instead of require("agent-deck.cli").
+--
+-- Supports two backends:
+--   "agent-deck" (default) — wraps cli.lua, sessions in tmux via agent-deck daemon
+--   "cmux"                 — native cmux surfaces, plugin is the daemon
+--
+-- init() must be called from setup() before any method is invoked.
+-- All interface methods are forwarded to the active backend implementation.
+local M = {}
+
+local log   = require("agent-deck.logger")
+local _impl = nil
+local _name = "agent-deck"  -- default backend
+
+--- Initialize the backend. Must be called once from setup().
+--- @param backend_name string|nil  "agent-deck" (default) or "cmux"
+function M.init(backend_name)
+  _name = backend_name or "agent-deck"
+  if _name == "cmux" then
+    _impl = require("agent-deck.backend.cmux")
+  else
+    _impl = require("agent-deck.backend.agent_deck")
+  end
+  log.info("backend.init: using '" .. _name .. "' backend")
+  -- Health check for cmux: verify app is running
+  if _impl.health_check then
+    _impl.health_check()
+  end
+end
+
+--- Return the active backend name ("agent-deck" or "cmux").
+function M.name()
+  return _name
+end
+
+-- ── Method forwarding ────────────────────────────────────────────────────────
+-- Every interface method is forwarded to the active backend implementation.
+-- assert(_impl) guards against calling before init().
+
+local METHODS = {
+  "status", "list_sessions", "session_show", "session_send",
+  "session_output", "session_start", "session_stop", "session_restart",
+  "session_delete", "launch", "group_list", "group_create",
+  "group_move", "session_set", "focus_session",
+}
+
+for _, method in ipairs(METHODS) do
+  M[method] = function(...)
+    assert(_impl, "backend.init() not called — call require('agent-deck').setup() first")
+    return _impl[method](...)
+  end
+end
+
+return M

lua/agent-deck/backend/agent_deck.lua

@@ -0,0 +1,23 @@
+-- backend/agent_deck.lua — thin wrapper over cli.lua for the backend interface
+--
+-- Re-exports all cli.lua methods unchanged and adds focus_session() as a
+-- no-op since agent-deck sessions live inside Neovim terminal buffers
+-- (focusing is handled by the picker/parallel UI layer, not the backend).
+local cli = require("agent-deck.cli")
+local M = setmetatable({}, { __index = cli })
+
+--- No-op for agent-deck backend: sessions live in Neovim terminals,
+--- so "focusing" is handled by the UI layer (picker/parallel).
+function M.focus_session(_, cb)
+  if cb then cb(true, nil) end
+end
+
+--- Health check: verify agent-deck binary is reachable.
+function M.health_check()
+  local bin = vim.fn.exepath("agent-deck")
+  if bin == "" then
+    require("agent-deck.logger").warn("agent_deck backend: binary not found in PATH")
+  end
+end
+
+return M

lua/agent-deck/backend/ansi.lua

@@ -0,0 +1,21 @@
+-- backend/ansi.lua — ANSI escape sequence stripping utility
+--
+-- Used by the cmux backend to clean raw terminal output from
+-- `cmux read-screen` before presenting it to the user.
+-- Strips CSI sequences, OSC sequences, single-char escapes,
+-- and carriage returns.
+local M = {}
+
+--- Strip ANSI escape sequences from terminal output text.
+--- Returns clean plain text suitable for display in a Neovim buffer.
+function M.strip(text)
+  if not text then return "" end
+  text = text:gsub("\27%[[\032-\063]*[\064-\126]", "")  -- CSI sequences (e.g. \27[0m, \27[38;5;12m)
+  text = text:gsub("\27%].-\a", "")                      -- OSC sequences (BEL terminated)
+  text = text:gsub("\27%].-\27\\", "")                   -- OSC sequences (ST terminated)
+  text = text:gsub("\27.", "")                            -- single-char escape sequences
+  text = text:gsub("\r", "")                              -- carriage returns
+  return text
+end
+
+return M