fix(cli, rfd)!: Stop the workspace picker recording a selection

[JeanMertz]

Answering the workspace picker recorded the choice as the session's active workspace, so a command run from outside every workspace asked once and then silently reused that answer. Standing in ~/scratch, jp c ls prompted, and the next jp c ls did not: a listing had acquired durable user-global state on the way past, and nothing said so on later runs, because the foreign-root notice stays quiet when the launch cwd has no workspace of its own to compete.

RFD 087 never said the picker records, and says the opposite everywhere else. The cwd-vs-active prompt separates c (use it now) from C (use it and make it session-active), which is a distinction the picker was quietly deciding on the user's behalf. jp w use is described as the command that mutates session state. And the whole surface is meant to mirror jp conversation, where the picker leaves the session mapping alone and only use, fork, and q write it. The picker now resolves the run and nothing more, so a session that never ran jp w use is asked again, exactly like a conversation that was never used. Resolution may still repair a recorded selection whose checkout is gone, but it never creates one: picker takes no session at all, so the invariant holds by construction rather than by review.

The bootstrap requirement declaration was not driving anything. run_inner returned early for jp w before reading it, leaving WorkspaceCommand::workspace_requirement unreachable and its Resolve variant dead behind that unreachable call. The declaration also described the wrong relationship: jp w show <id> reports on a workspace rather than running inside one, and jp w use <id> records a selection for later runs, so both resolve their own target against the pre-workspace TargetEnv and want no root selected for them. That is now a Subject requirement, and the startup dispatch matches on the requirement instead of on the command, so each arm performs exactly the pre-workspace work its commands asked for. Resolve had no client left once jp w use became Subject, and is dropped rather than kept for a hypothetical caller.

The targeting keyword for global recency becomes recent / r. jp conversation already spells this concept recent and reserves newest for the distinct one, so latest was a third word for something the grammar it borrows from names twice. RFD 087 was corrected to recent while this implementation was in flight, and merged without picking the change up.

BREAKING CHANGE: The l / latest workspace target is now r / recent

Spell jp -w latest as jp -w recent, and jp w use l as jp w use r. The old spellings are no longer keywords and fall through to fuzzy matching, so they will report no matching workspace rather than resolving. jp w use help lists the current grammar.