Plane client, transports and executor adapters

Plane: paginated issue/comment/state/label/member access, one client per
terminal identity. Transports: local (setsid-detached runner) and warpgate-ssh
(win10-ps.sh / win10-put.sh relay, schtasks launch, taskkill on timeout).
Executors share a runner shape (prompt.md, exit.txt marker) with codex,
claude-code and shell adapters for last message and thread id.

agentd/executors/__init__.py

@@ -0,0 +1,16 @@
+"""Executor adapters. `make_executor` picks the adapter class by the executor's `adapter` (default: its name)."""
+from .base import ExecResult, Executor, Run  # noqa: F401
+
+
+def make_executor(cfg, terminal, name, transport):
+    ecfg = cfg.executors[name]
+    adapter = ecfg.get("adapter", name)
+    if adapter == "codex":
+        from .codex import CodexExecutor as cls
+    elif adapter == "claude-code":
+        from .claude_code import ClaudeCodeExecutor as cls
+    elif adapter == "shell":
+        from .shell import ShellExecutor as cls
+    else:
+        raise ValueError("no executor adapter %s" % adapter)
+    return cls(name, ecfg, terminal, cfg.terminals[terminal], transport)