fix(build): prune devDependencies before shrinkwrapping (#1781)

Follow-up to #1622.

npm shrinkwrap runs after a full npm install in build-tools/build.sh, so the
generated npm-shrinkwrap.json captures devDependencies as well as runtime
ones. Since #1622 started shipping npm-shrinkwrap.json in the published
tarball, consumers now get harper's entire dev tree installed under
node_modules/harper/node_modules/ -- including esbuild (pulled in
transitively via tsx) and its ~30 platform-specific optional binaries.

Those nested @esbuild/<platform> entries land in the consumer's
package-lock.json as "extraneous" rather than resolved-optional, because
they aren't reachable from any declared dependency edge in the consumer's
graph -- they're just mirrored in from harper's bundled shrinkwrap.
Extraneous entries don't get the "optional": true flag written, so npm ci
in consumer projects fails with EBADPLATFORM on platforms other than the
shrinkwrap's original build machine (e.g. @esbuild/aix-ppc64 on
darwin/arm64).

Prune devDependencies before shrinkwrapping so the pinned tree only
contains what harper actually needs at runtime.

Co-authored-by: Peter Brumblay <pbrumblay@users.noreply.github.com>

Author: pbrumblay

build-tools/build.sh

@@ -8,6 +8,9 @@ npm install --ignore-scripts
 echo -e "\n📦 Building project"
 npm run build || true
 
+echo -e "\n📦 Pruning devDependencies"
+npm prune --omit=dev
+
 echo -e "\n📦 Creating shrinkwrap"
 npm shrinkwrap