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>

src/hooks/context-hook.ts

@@ -5,10 +5,20 @@
 
 import path from 'path';
 import { homedir } from 'os';
-import { existsSync, readFileSync } from 'fs';
+import { existsSync, readFileSync, unlinkSync } from 'fs';
 import { stdin } from 'process';
+import { fileURLToPath } from 'url';
+import { dirname } from 'path';
 import { SessionStore } from '../services/sqlite/SessionStore.js';
 
+// Get __dirname equivalent in ESM
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+// Version marker path (same as smart-install.js)
+// From src/hooks/ we need to go up to plugin root: ../../
+const VERSION_MARKER_PATH = path.join(__dirname, '../../.install-version');
+
 /**
  * Get context depth from settings
  * Priority: ~/.claude/settings.json > env var > default
@@ -156,7 +166,27 @@ async function contextHook(input?: SessionStartInput, useColors: boolean = false
   const cwd = input?.cwd ?? process.cwd();
   const project = cwd ? path.basename(cwd) : 'unknown-project';
 
-  const db = new SessionStore();
+  let db: SessionStore;
+  try {
+    db = new SessionStore();
+  } catch (error: any) {
+    if (error.code === 'ERR_DLOPEN_FAILED') {
+      // Native module ABI mismatch - delete version marker to trigger reinstall
+      try {
+        unlinkSync(VERSION_MARKER_PATH);
+      } catch (unlinkError) {
+        // Marker might not exist, that's okay
+      }
+
+      // Log once (not error spam) and exit cleanly
+      console.error('⚠️  Native module rebuild needed - restart Claude Code to auto-fix');
+      console.error('   (This happens after Node.js version upgrades)');
+      process.exit(0); // Exit cleanly to avoid error spam
+    }
+
+    // Other errors should still throw
+    throw error;
+  }
 
   // Get ALL recent observations for this project (not filtered by summaries)
   // This ensures we show observations even when summaries haven't been generated