v0.16.0

Added

• always_allowed_tools config key. Tools listed in it run without a permission prompt, in the TUI, over ACP (stdio and /ws), and for subagents. It matches the exact tool name ({server}__{tool} for MCP tools) and covers every call whatever its arguments, so listing execute_command allows every shell command. Also AppConfig::with_always_allowed_tools and OpenheimBuilder::always_allowed_tools, and GET /api/config now includes the list.
• --config <FILE> CLI flag, for running several agents with different configs at once. Every openheim subcommand takes it to load another config file instead of ~/.openheim/config.toml. History, skills, system.md, subagent profiles, the memory database and the TUI log live in the config's data_dir, or next to the file if it sets none. openheim --config FILE init creates the file and a system.md beside it. See "Config and data locations" in docs/deployment.md, including what isn't kept separate between agents (ports, [memory].db_path, work_dir).
• OpenheimClient::data_dir() returns the data directory the client resolved.
• config::init_config_at(config_path): init_config for a given config file, with system.md written next to it.

Changed

• The data directory defaults to the config file's directory. With .config_path(path) or OpenheimClient::from_config(path) and no data_dir (builder or config key), history, skills, system.md, subagent profiles and memory.db now live next to path instead of in ~/.openheim. Embedders who relied on the old default should add .data_dir(openheim::config::config_dir()?). Without a custom config path nothing changes: the default config is ~/.openheim/config.toml, so the data stays in ~/.openheim.