A project Host inherited the operator's handoffs

An isolated browser acceptance run opened a fresh Host with its own signing identity, an explicit configuration directory, no relay and no chat channels. The browser task had not run when unrelated handoff notices began appearing in its log.

The Host was isolated at the request boundary. Its startup work was not. host() called _create_handoff_lifespan() without passing the configuration directory. The watcher then selected the ambient configuration, where the operator's pending handoffs lived. That watcher can update seen records, remember peers and send notifications or automatic replies. Starting it is more than reading a status feed.

The run was stopped and its evidence retained. The private log was enough to confirm that global persistence paths had executed. It was not enough to establish every possible outbound effect, so this is not a claim that no notification occurred. No private handoff contents are included here, and historical records are not reset as a repair: resetting them could cause repeated notifications or session copies.

The bounded change passes the Host's configuration directory into startup and starts the existing watcher only when that resolved directory owns the configured handoff store. A different project Host does not start an ambient watcher. A matching configured directory retains the original start and shutdown behavior. The owner's CLI watcher is unchanged.

This deliberately does not implement project handoff queues by temporarily switching process environment. A watcher runs on a thread, and changing an environment variable would change the meaning of configuration for every other thread too. Per-project handoff transport and persistence would need an explicit contract of their own.

The regressions use temporary directories and a watcher spy: separate Host ownership never starts the watcher, matching and normalized directory paths retain start/shutdown, and the public Host passes its directory through. They do not read a real mailbox, global handoff records or customer data. This source change still requires its normal PR checks and release acceptance; the browser pacing patch is a separate change.