refactor: unify instance path resolution and preserve workspace override

tests/test_config_paths.py

@@ -0,0 +1,42 @@
+from pathlib import Path
+
+from nanobot.config.paths import (
+    get_bridge_install_dir,
+    get_cli_history_path,
+    get_cron_dir,
+    get_data_dir,
+    get_legacy_sessions_dir,
+    get_logs_dir,
+    get_media_dir,
+    get_runtime_subdir,
+    get_workspace_path,
+)
+
+
+def test_runtime_dirs_follow_config_path(monkeypatch, tmp_path: Path) -> None:
+    config_file = tmp_path / "instance-a" / "config.json"
+    monkeypatch.setattr("nanobot.config.paths.get_config_path", lambda: config_file)
+
+    assert get_data_dir() == config_file.parent
+    assert get_runtime_subdir("cron") == config_file.parent / "cron"
+    assert get_cron_dir() == config_file.parent / "cron"
+    assert get_logs_dir() == config_file.parent / "logs"
+
+
+def test_media_dir_supports_channel_namespace(monkeypatch, tmp_path: Path) -> None:
+    config_file = tmp_path / "instance-b" / "config.json"
+    monkeypatch.setattr("nanobot.config.paths.get_config_path", lambda: config_file)
+
+    assert get_media_dir() == config_file.parent / "media"
+    assert get_media_dir("telegram") == config_file.parent / "media" / "telegram"
+
+
+def test_shared_and_legacy_paths_remain_global() -> None:
+    assert get_cli_history_path() == Path.home() / ".nanobot" / "history" / "cli_history"
+    assert get_bridge_install_dir() == Path.home() / ".nanobot" / "bridge"
+    assert get_legacy_sessions_dir() == Path.home() / ".nanobot" / "sessions"
+
+
+def test_workspace_path_is_explicitly_resolved() -> None:
+    assert get_workspace_path() == Path.home() / ".nanobot" / "workspace"
+    assert get_workspace_path("~/custom-workspace") == Path.home() / "custom-workspace"