chore: add SessionStart hook for Claude Code on the web

Set up dev environment automation so remote Claude Code sessions
automatically install dependencies and build packages on startup.

- Add .claude/hooks/session-start.sh (pnpm install + pnpm build)
- Add .claude/settings.json to register the SessionStart hook
- Add pnpm.onlyBuiltDependencies for esbuild and @parcel/watcher

https://claude.ai/code/session_0153jtsmYXCuyedMWwv88aWP

Author: claude

.claude/hooks/session-start.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -euo pipefail
+
+# Only run in remote (Claude Code on the web) environments
+if [ "${CLAUDE_CODE_REMOTE:-}" != "true" ]; then
+  exit 0
+fi
+
+cd "$CLAUDE_PROJECT_DIR"
+
+# Install all workspace dependencies
+pnpm install
+
+# Build all packages (downstream packages depend on upstream builds)
+pnpm build

.claude/settings.json

@@ -0,0 +1,14 @@
+{
+  "hooks": {
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "$CLAUDE_PROJECT_DIR/.claude/hooks/session-start.sh"
+          }
+        ]
+      }
+    ]
+  }
+}

package.json

@@ -16,5 +16,11 @@
   },
   "devDependencies": {
     "@changesets/cli": "^2.29.8"
+  },
+  "pnpm": {
+    "onlyBuiltDependencies": [
+      "@parcel/watcher",
+      "esbuild"
+    ]
   }
 }