Add SessionStart hook for Claude Code Remote

Configure the Bun repository for Claude Code Remote sessions:

- Add session-start.sh hook that runs on session startup
- Fix /tmp permissions if needed (must be 1777)
- Fix Python alternatives for apt_pkg compatibility
- Run bootstrap.sh to install build dependencies (LLVM 19, Node.js, etc.)
- Set up clang-19 as default compiler with proper symlinks
- Persist environment variables (PATH, CC, CXX) for the session
- Install npm dependencies for main and test directories
- Build bun-debug binary

The hook only runs in Claude Code Remote environments (checks
CLAUDE_CODE_REMOTE env var).

.claude/hooks/session-start.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+set -euo pipefail
+
+# Only run in Claude Code Remote environment
+if [ "${CLAUDE_CODE_REMOTE:-}" != "true" ]; then
+  exit 0
+fi
+
+cd "$CLAUDE_PROJECT_DIR"
+
+# Fix /tmp permissions if needed (must be world-writable with sticky bit)
+if [ "$(stat -c %a /tmp 2>/dev/null)" != "1777" ]; then
+  echo "Fixing /tmp permissions..."
+  chmod 1777 /tmp 2>/dev/null || true
+fi
+
+# Ensure /usr/local/bin takes precedence for bootstrap-installed tools
+export PATH="/usr/local/bin:$PATH"
+
+# Fix Python alternatives if apt_pkg module is missing
+if ! /usr/bin/python3 -c "import apt_pkg" 2>/dev/null; then
+  echo "Fixing Python alternatives for apt_pkg..."
+  if [ -f /usr/bin/python3.12 ]; then
+    update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.12 1 2>/dev/null || true
+    update-alternatives --set python3 /usr/bin/python3.12 2>/dev/null || true
+  fi
+fi
+
+echo "Running bootstrap to set up build dependencies..."
+./scripts/bootstrap.sh || echo "Bootstrap had some errors, continuing..."
+
+# Set up clang as default compiler if not already done
+if [ -f /usr/bin/clang-19 ] && [ ! -L /usr/bin/cc ] || [ "$(readlink /usr/bin/cc 2>/dev/null)" != "/usr/bin/clang" ]; then
+  echo "Setting up clang-19 as default compiler..."
+  ln -sf /usr/bin/clang-19 /usr/bin/clang 2>/dev/null || true
+  ln -sf /usr/bin/clang++-19 /usr/bin/clang++ 2>/dev/null || true
+  ln -sf /usr/bin/clang /usr/bin/cc 2>/dev/null || true
+  ln -sf /usr/bin/clang++ /usr/bin/c++ 2>/dev/null || true
+  ln -sf /usr/bin/lld-19 /usr/bin/lld 2>/dev/null || true
+  ln -sf /usr/bin/ld.lld-19 /usr/bin/ld.lld 2>/dev/null || true
+  ln -sf /usr/bin/llvm-ar-19 /usr/bin/llvm-ar 2>/dev/null || true
+  ln -sf /usr/bin/llvm-symbolizer-19 /usr/bin/llvm-symbolizer 2>/dev/null || true
+fi
+
+# Persist environment variables for the session
+if [ -n "${CLAUDE_ENV_FILE:-}" ]; then
+  echo 'export PATH="/usr/local/bin:$PATH"' >> "$CLAUDE_ENV_FILE"
+  echo 'export CC=/usr/bin/clang' >> "$CLAUDE_ENV_FILE"
+  echo 'export CXX=/usr/bin/clang++' >> "$CLAUDE_ENV_FILE"
+fi
+
+echo "Installing main dependencies..."
+bun install
+
+echo "Installing test dependencies..."
+bun install --cwd test --ignore-scripts
+
+echo "Building bun-debug..."
+bun run build
+
+echo "Session start hook completed successfully."

.claude/settings.json

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