fix: complete better-sqlite3 to bun:sqlite migration

Must Fix:
- Remove better-sqlite3 logic from smart-install.js (5 sections)
- Update all documentation to reference bun:sqlite (7 files)

Should Fix:
- Add defensive break statement in worker-cli.ts:38

Nice to Have:
- Add port validation in ProcessManager.start() (1024-65535)
- Add one-time marker for PM2 cleanup migration
- Verify clearPortCache() wiring (already correct)

Addresses PR #248 review feedback (comment #3648517713)

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/services/process/ProcessManager.ts

@@ -25,6 +25,14 @@ interface PidInfo {
 
 export class ProcessManager {
   static async start(port: number): Promise<{ success: boolean; pid?: number; error?: string }> {
+    // Validate port range
+    if (isNaN(port) || port < 1024 || port > 65535) {
+      return {
+        success: false,
+        error: `Invalid port ${port}. Must be between 1024 and 65535`
+      };
+    }
+
     // Check if already running
     if (await this.isRunning()) {
       const info = this.getPidInfo();