feat: Auto-detect and rebuild native modules on Node.js version changes (#149)

Implements three-layer defense against native module version mismatches:

Layer 1: Node.js Version Tracking
- Track Node.js version alongside package version in .install-version marker
- Auto-trigger npm install when Node.js version changes
- Backward compatible with old plain-text version marker format

Layer 2: Native Module Verification
- Add verifyNativeModules() function to test better-sqlite3 loads correctly
- Verify after install completes to catch corrupted builds
- Retry with force flag if initial install verification fails

Layer 3: Graceful Failure
- Catch ERR_DLOPEN_FAILED in context-hook and delete version marker
- Exit cleanly to avoid error spam in Claude Code UI
- Auto-fix on next session start

Changes:
- scripts/smart-install.js: Add Node.js version tracking and verification
- src/hooks/context-hook.ts: Add graceful failure handling for native module errors
- tests/smart-install.test.js: Add tests for version marker format compatibility
- plugin/scripts/context-hook.js: Built output from TypeScript source

Fixes the issue where users see ERR_DLOPEN_FAILED errors after Node.js upgrades,
requiring manual npm install. Now automatically detects and fixes the issue.

Related design doc: docs/context/native-module-auto-fix-design.md
Implementation plan: docs/context/native-module-auto-fix-implementation.md

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

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Alex Newman <thedotmack@gmail.com>

tests/smart-install.test.js

@@ -0,0 +1,47 @@
+import { test } from 'node:test';
+import assert from 'node:assert';
+import { existsSync, readFileSync, writeFileSync, unlinkSync } from 'fs';
+import { join } from 'path';
+
+const VERSION_MARKER_PATH = join(process.cwd(), '.install-version');
+
+test('version marker - new JSON format', () => {
+  const marker = {
+    packageVersion: '6.3.2',
+    nodeVersion: 'v22.21.1',
+    installedAt: new Date().toISOString()
+  };
+
+  writeFileSync(VERSION_MARKER_PATH, JSON.stringify(marker, null, 2));
+  const content = JSON.parse(readFileSync(VERSION_MARKER_PATH, 'utf-8'));
+
+  assert.strictEqual(content.packageVersion, '6.3.2');
+  assert.strictEqual(content.nodeVersion, 'v22.21.1');
+  assert.ok(content.installedAt);
+
+  unlinkSync(VERSION_MARKER_PATH);
+});
+
+test('version marker - backward compatibility with old format', () => {
+  // Old format: plain text version string
+  writeFileSync(VERSION_MARKER_PATH, '6.3.2');
+  const content = readFileSync(VERSION_MARKER_PATH, 'utf-8').trim();
+
+  // Should be able to parse old format
+  let marker;
+  try {
+    marker = JSON.parse(content);
+  } catch {
+    // Old format - create compatible object
+    marker = {
+      packageVersion: content,
+      nodeVersion: null,
+      installedAt: null
+    };
+  }
+
+  assert.strictEqual(marker.packageVersion, '6.3.2');
+  assert.strictEqual(marker.nodeVersion, null);
+
+  unlinkSync(VERSION_MARKER_PATH);
+});