feat: rename skills/skiff to pouch and move ACK state under .pouch

Use ~/.pouch, the pouch CLI, and .pouch.yaml as the SSOT container.
Keep the inner skills/ packages, and store ACK project state in
.pouch/ack instead of docs/ack.

pouch/agents.py

@@ -0,0 +1,40 @@
+"""Agent 名称解析（兼容 Vercel skills CLI 别名）。"""
+
+from __future__ import annotations
+
+from pouch.paths import ALL_TARGETS
+
+AGENT_ALIASES: dict[str, str] = {
+    "cursor": "cursor",
+    "claude": "claude",
+    "claude-code": "claude",
+    "codex": "codex",
+    "agents": "agents",
+}
+
+AGENT_CHOICES = sorted({*ALL_TARGETS, *AGENT_ALIASES.keys()})
+
+
+def flatten_agent_args(groups: list[list[str]] | None) -> list[str] | None:
+    if not groups:
+        return None
+    flat = [item for group in groups for item in group]
+    return flat or None
+
+
+def resolve_agent_args(agents: list[str] | None) -> list[str]:
+    if not agents or agents == ["*"] or "*" in agents:
+        return list(ALL_TARGETS)
+
+    resolved: list[str] = []
+    for raw in agents:
+        key = raw.lower()
+        if key == "*":
+            return list(ALL_TARGETS)
+        target = AGENT_ALIASES.get(key)
+        if target is None:
+            choices = ", ".join(AGENT_CHOICES)
+            raise SystemExit(f"未知 agent: {raw!r}，可选: {choices}")
+        if target != "*" and target not in resolved:
+            resolved.append(target)
+    return resolved