chore(claude): add SessionStart hook for Claude Code on the web

Installs workspace dependencies (pnpm install) on session start so that
turbo, biome, and other tools work out of the box without a devcontainer.
Mirrors the setup performed by .devcontainer/app/postCreateCommand.sh.

https://claude.ai/code/session_019Mh5cVjsoTfZnxVjamHkvf

.claude/hooks/session-start.sh

@@ -0,0 +1,22 @@
+#!/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.
+# turbo (root devDependency) and all workspace packages will be installed.
+pnpm install
+
+# Install turbo globally (mirrors devcontainer postCreateCommand.sh) so it is
+# available as a bare `turbo` command in subsequent Claude tool calls.
+# Falls back to adding node_modules/.bin to PATH if the pnpm global store is
+# not yet configured in this environment.
+if ! command -v turbo &> /dev/null; then
+  pnpm install turbo --global 2>/dev/null \
+    || echo "export PATH=\"$CLAUDE_PROJECT_DIR/node_modules/.bin:\$PATH\"" >> "$CLAUDE_ENV_FILE"
+fi

.claude/settings.json

@@ -1,5 +1,15 @@
 {
   "hooks": {
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "$CLAUDE_PROJECT_DIR/.claude/hooks/session-start.sh"
+          }
+        ]
+      }
+    ],
     "PostToolUse": [
       {
         "matcher": "Write|Edit",