perf(prepush): share pro-test npm and vite caches across worktrees

[koala73]

Summary

A fresh worktree that tripped the pro-test freshness gate used to spend ~55s on npm ci + vite build before it even compared public/pro/. After this change the same gate still fails a stale marketing bundle, but the install and Vite cache are shared across worktrees instead of being paid again on every checkout.

Closes #6766.

What changed

npm ci at the hook's admission-leased install site and in worktree bootstrap now passes --prefer-offline against the existing /tmp/worldmonitor-npm-cache. Bootstrap also seeds pro-test/node_modules (copy/npm ci, never a node_modules symlink — that path is known-broken here).

Vite's default node_modules/.vite is linked at hook time to a lockfile-sharded directory under the same git-common-dir that #6846 uses for admission, so every worktree of the same repo and lockfile shares one cache. Concurrent hook builds take a flock on that directory.

pro-test/vite.config.ts is intentionally untouched. Editing it would put pro-test/ in the branch delta, fire this same gate, and force a public/pro/ rebuild. On this machine a clean rebuild of current main already produces different hashed assets than the committed production bytes — a pre-existing drift, not something this cache change should ship.

Measurements

Issue report (curious-frolicking-kite, 2026-08-16):

step	cold	warm
pro-test npm ci	23.6s	skipped
pro-test npm run build	31.3s	7.1s
total	54.9s	7.1s

This worktree (Node 24.19, after npm ci --prefer-offline):

step	result
pro-test npm ci --prefer-offline	40.7s (tarball extract; no network when cache is warm)
vite build first run	22.5s
vite build second run	21.8s
two concurrent vite builds	both exit 0, byte-identical outputs (42 files)
cacheDir vs default output	identical
full generate-product-config + npm run build	28.8s; this machine's hashed assets still differ from committed public/pro/ (pre-existing)

The ≤20s first-push target is the bootstrap-seeded path: pro-test/node_modules is already present, so the hook skips npm ci and only rebuilds. Production vite build did not write a cacheDir on this machine, so the 31s→7s warm number from the issue is likely OS page cache + an already-installed tree more than a Vite dep-optimize hit.

Test plan

• Hook fixture: missing pro-test/node_modules runs npm ci --prefer-offline
• Hook fixture: a pro-test/node_modules symlink is refused and does not run npm ci
• Hook fixture: .vite is a link into wm-vite-cache/pro-test-<hash>; node_modules itself is not a symlink
• Hook fixture: reverting one byte of committed public/pro/index.html still fails with the existing stale-bundle error
• Bootstrap dry-run seeds pro-test and includes --prefer-offline
• Bootstrap refuses a node_modules symlink instead of following it
• Cache resolver: env override, lockfile shard, same lockfile → same path, missing git → fallback
• Two concurrent Vite builds, outputs hashed equal
• Gate trigger list and git diff paths unchanged
• Rebased onto fix(prepush): bound concurrent heavy gates #6846; root npm ci stays under the admission lease

Known Residuals

• pro-test/vite.config.ts does not set cacheDir. The hook shares Vite's default cache directory instead, so this PR does not have to rebuild public/pro/.
• Dedicated multi-persona ce-code-review did not finish (reviewer hung). Orchestrator reviewed correctness, gate regressions, and the symlink landmine locally.

Post-Deploy Monitoring & Validation

No additional operational monitoring required. This only changes the local pre-push hook and worktree bootstrap. Production /pro bytes are not in the diff; a stale committed bundle still fails the same hook error.

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Project	Deployment	Actions	Updated (UTC)
worldmonitor	Ready	Preview	Aug 17, 2026 12:32pm