fix(vercel): run install command from monorepo root to access workspace packages

**Problem:**
Vercel deployments were failing with:
```
ERR_PNPM_NO_MATCHING_VERSION_INSIDE_WORKSPACE: No matching version found for @tpmjs/eslint-config@* inside the workspace
```

The `installCommand` was running `pnpm install` from `apps/web`, which couldn't access workspace packages defined at the monorepo root.

**Solution:**
Change `installCommand` from `pnpm install` to `cd ../.. && pnpm install` to run from the monorepo root, matching the `buildCommand` behavior.

**Impact:**
- Vercel can now find and install all workspace packages
- Deployments should succeed
- All previous tool execution fixes can now actually deploy

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/web/vercel.json

@@ -1,5 +1,5 @@
 {
   "$schema": "https://openapi.vercel.sh/vercel.json",
   "buildCommand": "cd ../.. && pnpm install && pnpm --filter=@tpmjs/web...  build",
-  "installCommand": "pnpm install"
+  "installCommand": "cd ../.. && pnpm install"
 }