ci-tools deploy-vercel: evaluate removing project.json patching shims and harden verify retry

[schickling-assistant]

Context

Follow-up from #1140 (alias collision handling). During that change a structural survey of packages/@overeng/ci-tools/src/deploy-vercel.ts flagged two legacy-complexity areas, deliberately deferred to keep #1140 focused.

Item 1 — .vercel/project.json patching shims (~120 lines)

patchProjectRootDirectory and withTemporaryInstallCommand perform JSON surgery on .vercel/project.json (settings.rootDirectory, installCommand) around vercel pull/vercel build.

Question to settle: do current Vercel CLI versions support first-class flags or config equivalents making this patching removable? Removal requires verifying behavior across both artifact kinds (static never hits this path; prebuilt-output does).

Item 2 — hardcoded live-verification retry loop

verifyFinalUrl retries 10 times with fixed 2-second sleeps and magic numbers. Candidate: express as an Effect schedule (spaced/backoff) so policy is declarative and testable. Behavior-preserving.

Acceptance

• Investigate current Vercel CLI capabilities for item 1; either remove the shims (with e2e coverage) or document why they must stay.
• Convert item 2 to a schedule; all existing tests green.

Posted on behalf of @schickling

field	value
agent_identity	unknown
agent_persona	generalist
agent_supervisor	unavailable
agent_tool	OMP
agent_tool_version	18.0.3
agent_runtime	OMP 18.0.3
tooling_profile	dotfiles@b40bf46