* feat(agent-launch): let a caller reserve the chat session and carry session picks to a terminal launch
* fix(agent-launch): keep a caller-minted session id named for its agent, and mint the fallback the same way
* test(mobile): model the older host from the launch fields, not the refined schema
* docs(agent-launch): describe the reserved session id as conversation identity, not placement
The caller mints the session id so it knows which conversation it
started; tab placement is not keyed on it. Also puts the terminal
surface's doc comment back on createTerminalSurface.
* docs(agent-launch): say a terminal launch reads the session picks on the wire contract
The `sessionOptions` field doc still said a terminal launch ignores them, which this branch changed.
* fix(agent-launch): check a reserved session id's token after the agent name, not the whole id
A hyphenated agent name failed the one-token check, so any session id for such an agent was
refused at the wire, while every other agent without a chat has its id ignored on the terminal.
