bug: source upgrade can exceed controller timeout without progress output

[chubes4]

Reproduction

1. Materialize a clean source worktree at accepted origin/main commit b2cb9d1, including fix: package verified source for deploy refs #7851, fix: preserve local source identity for runner upgrades #7866, Fix detached agent-task ghost-run liveness #7867, and fix: return source workspace preparation result #7873.
2. Run homeboy upgrade --method source --source-path /Users/chubes/Developer/homeboy@ops-rollout-accepted-main-7873 --force.
3. Observe no stdout or stderr and no completion within 120 seconds.

Expected

The supported source-upgrade workflow completes or emits phase/progress output sufficient to distinguish compilation from a stall.

Actual

The controller execution timed out after 120 seconds with no command output. The rollout was stopped before any deploy or runtime mutation.

Context

The active binary remains homeboy 0.282.1+b2cb9d152919 at the requested source commit, but this does not establish that the forced source-install workflow completed. This follows #7873, which fixes #7871.