fix: break-C — install-hooks no-ops without git; web image builds @mosaicstack/web

install-hooks.mjs hard-failed (exit 1) in environments without a git
binary — e.g. the docker image builds, which have no git and no repo.
Hook installation is meaningless there; skip with a warning instead.

docker/web.Dockerfile filtered @mosaic/web, but the package is named
@mosaicstack/web, so the image build compiled nothing.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01ESFAnh2t9HmLwng8oW95St

docker/web.Dockerfile

@@ -10,7 +10,7 @@ COPY apps/web/package.json ./apps/web/
 COPY packages/ ./packages/
 RUN pnpm install --frozen-lockfile
 COPY . .
-RUN pnpm --filter @mosaic/web build
+RUN pnpm --filter @mosaicstack/web build
 
 FROM base AS runner
 WORKDIR /app

scripts/install-hooks.mjs

@@ -75,6 +75,16 @@ export async function installHooks({
 } = {}) {
   if (disabled) return;
 
+  try {
+    await execFileAsync('git', ['--version']);
+  } catch (error) {
+    if (error.code === 'ENOENT') {
+      console.warn('git not found; skipping hook installation');
+      return;
+    }
+    throw error;
+  }
+
   const huskyDir = path.join(root, '.husky');
   const active = path.join(huskyDir, '_');
   const nonce = `${Date.now()}-${process.pid}`;