Clean up repository hygiene

- Expand .gitignore with editor state, secrets, logs, and archive patterns
- Remove AdminCategoriesViewV2.vue (replaced, no remaining references)
- Exclude accidental AdminContentView duplicate from tsconfig

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

.gitignore

@@ -3,7 +3,38 @@ frontend/dist/
 Backend/bin/
 Backend/obj/
 .DS_Store
+
+# Editor and local machine state
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# Environment and secrets
+.env
+.env.*
+!.env.example
+!.env.template
+*.local
+*.secret
+*.secrets
+*.key
+*.pem
+*.p12
+*.pfx
+
+# Logs and diagnostics
+*.log
+logs/
+log/
+
 *.zip
+*.tar
+*.tar.gz
+*.tgz
+*.rar
+*.7z
 *.docx
 
 # Local Claude Code config (settings, preview launch configs)