chore: add Claude Code PostToolUse syntax-check hook

.claude/settings.json — hook fires after every Edit/Write:
- .js files  → node --check
- .py files  → py_compile.compile (doraise=True)
- exit 2 on failure → Claude sees the error immediately and fixes it

Scripts:
- .claude/hooks/syntax_check.ps1  (Windows, primary)
- .claude/hooks/syntax_check.sh   (bash fallback)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/hooks/syntax_check.ps1

@@ -0,0 +1,41 @@
+# ================================================================
+# Claude Code — PostToolUse hook (Windows PowerShell fallback)
+# Syntax check after every Edit / Write tool call.
+# Exit code 2 = Claude sees the error and can fix immediately.
+# ================================================================
+
+param()
+
+# Read file_path from CLAUDE_TOOL_INPUT env var (JSON)
+$filePath = ""
+try {
+    $input_json = $env:CLAUDE_TOOL_INPUT | ConvertFrom-Json -ErrorAction Stop
+    $filePath = $input_json.file_path
+} catch {}
+
+if (-not $filePath -or -not (Test-Path $filePath)) { exit 0 }
+
+$ext = [System.IO.Path]::GetExtension($filePath).TrimStart('.')
+
+switch ($ext) {
+    "js" {
+        $result = & node --check $filePath 2>&1
+        if ($LASTEXITCODE -ne 0) {
+            Write-Output "❌ JS SYNTAX ERROR: $filePath"
+            Write-Output $result
+            exit 2
+        }
+    }
+    "py" {
+        $escaped = $filePath -replace "'", "''"
+        $result = & python -c "import py_compile,sys; py_compile.compile('$escaped', doraise=True)" 2>&1
+        if ($LASTEXITCODE -ne 0) {
+            Write-Output "❌ PY SYNTAX ERROR: $filePath"
+            Write-Output $result
+            exit 2
+        }
+    }
+    default { exit 0 }
+}
+
+exit 0

.claude/hooks/syntax_check.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+# =============================================================
+# Claude Code — PostToolUse hook: syntax check after Edit/Write
+# Reads tool input JSON from stdin, extracts file_path,
+# runs language-appropriate syntax check.
+# Exit 2 → Claude sees the error and can fix it immediately.
+# =============================================================
+
+set -euo pipefail
+
+# Parse file_path from JSON stdin (jq if available, else python fallback)
+if command -v jq &>/dev/null; then
+  FILE_PATH=$(echo "$CLAUDE_TOOL_INPUT" | jq -r '.file_path // empty' 2>/dev/null || true)
+else
+  FILE_PATH=$(python3 -c "
+import sys, json
+try:
+    d = json.loads(sys.stdin.read())
+    print(d.get('file_path', ''))
+except Exception:
+    pass
+" <<< "$CLAUDE_TOOL_INPUT" 2>/dev/null || true)
+fi
+
+# Also try env var set by Claude Code
+FILE_PATH="${FILE_PATH:-${CLAUDE_TOOL_INPUT_FILE_PATH:-}}"
+
+if [[ -z "$FILE_PATH" || ! -f "$FILE_PATH" ]]; then
+  exit 0
+fi
+
+EXT="${FILE_PATH##*.}"
+
+case "$EXT" in
+  js)
+    if ! OUTPUT=$(node --check "$FILE_PATH" 2>&1); then
+      echo "❌ JS SYNTAX ERROR: $FILE_PATH"
+      echo "$OUTPUT"
+      exit 2
+    fi
+    ;;
+  py)
+    if ! OUTPUT=$(python3 -c "
+import py_compile, sys
+try:
+    py_compile.compile('$FILE_PATH', doraise=True)
+except py_compile.PyCompileError as e:
+    print(e)
+    sys.exit(1)
+" 2>&1); then
+      echo "❌ PY SYNTAX ERROR: $FILE_PATH"
+      echo "$OUTPUT"
+      exit 2
+    fi
+    ;;
+  *)
+    # Остальные типы файлов — пропускаем
+    exit 0
+    ;;
+esac
+
+exit 0

.claude/settings.json

@@ -0,0 +1,15 @@
+{
+  "hooks": {
+    "PostToolUse": [
+      {
+        "matcher": "Edit|Write",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "powershell -NonInteractive -File \".claude\\hooks\\syntax_check.ps1\""
+          }
+        ]
+      }
+    ]
+  }
+}