create: post_create hook failures exit 0 by default (best-effort) — an empty-DB worktree reads as successfully 'created'

[ikeikeikeike]

Context

Follow-up (UX) from the mysql readiness-race investigation whose root cause is fixed in #90 / v0.9.29. Ranked #4 in that handover.

Problem

bough create is best-effort by default: --strict (internal/cli/create.go:60) is false unless passed, so once the worktree directory exists the command exits 0 even if every post_create DB hook failed. The only signal is a WARNING line (create.go:198):

[bough] WARNING: create finished with N problem(s); the worktree exists but its environment may be incomplete: ...

When create-database → migrate → seed-force all fail (e.g. the readiness race this repo just fixed, or any future post_create breakage), the worktree looks "created" and claude --worktree proceeds into it. The user only discovers the empty DB later, when the app can't find its tables — far from the actual failure.

Proposal (pick one / discuss)

1. Make post_create DB-hook failures non-zero by default (invert --strict, or add a narrower default-on gate for post_create specifically while keeping worktree-add best-effort).
2. Keep exit 0 but make the failure summary much more prominent — e.g. a boxed/colored final summary that names each failed hook and the remediation (bough remove --name X / re-run), instead of a single WARNING line that scrolls past.
3. At minimum, document the --strict flag prominently in the README/quickstart so CI and scripted bough create callers opt into it.

Notes

• The --strict mechanism already exists (create.go:60, error at :209) — this issue is about the default and visibility, not a missing capability.
• Related but distinct: bough create: engine-provider repo's git worktree add fails (exit 128), then bough writes .env.local + runs post_create into the broken dir and still exits 0 #41 (closed; specific git-worktree-add-broken-dir exit-0 case).