feat: Release v4.0.5 - Auto-install dependencies via bootstrap hooks

Fixed better-sqlite3 distribution by implementing self-bootstrapping hooks
that auto-install dependencies on first run. This eliminates the need for
users to have native compilation tools or manually install dependencies.

## Solution

Instead of bundling 25MB of better-sqlite3 binaries in git or requiring
manual npm install, hooks now bootstrap themselves on first execution:

1. Created `src/shared/bootstrap.ts` with `ensureDependencies()` function
2. Added bootstrap calls to all hook entry points (context, new, save, summary, cleanup)
3. Created `plugin/scripts/package.json` declaring better-sqlite3 dependency
4. Bootstrap checks if `node_modules` exists, runs `npm install` if missing
5. npm automatically downloads prebuilt better-sqlite3 binary for user's platform

## Changes

**Core Bootstrap System:**
- Added src/shared/bootstrap.ts: Auto-install dependencies using npm
- Modified all hooks (context, new, save, summary, cleanup) to call ensureDependencies()
- Created plugin/scripts/package.json with better-sqlite3 dependency

**Build & Distribution:**
- Removed node_modules copying logic from build script
- Build output is now compact (hooks + package.json, no binaries)
- Updated marketplace.json to point to GitHub for direct installation

**Documentation:**
- Updated README: GitHub Marketplace installation is now recommended method
- Installation instructions emphasize no compilation needed
- Version bumped to 4.0.5 throughout

## Benefits

- ✅ No git bloat (repo stays small, no 25MB binaries committed)
- ✅ No compilation needed (npm downloads prebuilt binaries)
- ✅ Works on all platforms (npm handles platform-specific binaries)
- ✅ Zero manual steps (hooks bootstrap themselves automatically)
- ✅ Idempotent (skips install if dependencies already exist)

Installation now works via simple:
```
/plugin marketplace add https://github.com/thedotmack/claude-mem
/plugin install claude-mem
```

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

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

src/shared/bootstrap.ts

@@ -0,0 +1,44 @@
+import { execSync } from 'child_process';
+import { existsSync } from 'fs';
+import { join } from 'path';
+
+/**
+ * Bootstrap function to ensure dependencies are installed
+ * This runs on first hook execution after plugin installation from GitHub
+ *
+ * When installed via GitHub Marketplace, files are downloaded but npm install
+ * doesn't run automatically. This function checks for node_modules and installs
+ * dependencies if needed.
+ */
+export function ensureDependencies(): void {
+  try {
+    // Get plugin root from environment variable
+    const pluginRoot = process.env.CLAUDE_PLUGIN_ROOT;
+    if (!pluginRoot) {
+      console.error('[bootstrap] CLAUDE_PLUGIN_ROOT not set, skipping dependency check');
+      return;
+    }
+
+    const scriptsDir = join(pluginRoot, 'scripts');
+    const nodeModulesPath = join(scriptsDir, 'node_modules');
+
+    // Check if dependencies are already installed
+    if (existsSync(nodeModulesPath)) {
+      return; // Already installed
+    }
+
+    console.error('[bootstrap] Installing dependencies in plugin/scripts...');
+
+    // Install dependencies using npm
+    execSync('npm install', {
+      cwd: scriptsDir,
+      stdio: 'inherit', // Show install progress
+      timeout: 60000 // 60 second timeout
+    });
+
+    console.error('[bootstrap] Dependencies installed successfully');
+  } catch (error) {
+    console.error('[bootstrap] Failed to install dependencies:', error instanceof Error ? error.message : error);
+    // Don't throw - allow hook to continue, it will fail on import but with clearer error
+  }
+}