SessionStart/PreCompact hooks run npm install on every invocation: 5-minute stall on claude --resume

[memmmmike]

Problem

hooks/hooks.json prefixes both the SessionStart and PreCompact hooks with:

npm install --silent --prefix ${CLAUDE_PLUGIN_ROOT} --omit=dev --no-audit --no-fund >/dev/null 2>&1 && node ...

This runs a full npm install on every session start and every compaction, even when node_modules is already populated. With the shipped 73MB package-lock.json, that install takes ~5 minutes of pure CPU on my machine (Fedora, npm 10.x):

real    5m2.947s
user    5m2.375s
sys     0m3.994s

Net effect: every claude --continue / claude --resume hangs for ~5 minutes before the prompt is usable, and PreCompact stalls compaction the same way. Because the install is silenced, there is no indication of what is blocking.

Fix

Guard the install so it only runs when dependencies are missing:

[ -d "${CLAUDE_PLUGIN_ROOT}/node_modules" ] || npm install --silent --prefix ${CLAUDE_PLUGIN_ROOT} --omit=dev --no-audit --no-fund >/dev/null 2>&1; node ${CLAUDE_PLUGIN_ROOT}/hooks/session-start.js

(and the same for the PreCompact command.)

With the guard, the hook completes in 0.11s. npm ci with the guard would also work and is more reproducible. Alternatively, run the install once at plugin install time rather than per-hook.

Plugin version: 0.2.8.