feat: multi-database backup, HTTP API endpoints, admin panel UI

- backup CLI: add --all-databases, --database, --data-root flags
- backup format: tar.gz with databases/<name>/ + backup.json metadata
- HTTP API: new endpoints /databases, /backup, /backups, /restore
- HTTP API: database switching via X-Database header
- Admin panel: database selector dropdown, Databases tab, Backups tab
- Admin panel: backup/restore UI with fetch() to new endpoints
- Update deps: hunos 1.3.0, jwt-nim-baraba 2.1.0
- Docker: backup cron uses --all-databases --data-root=/data/databases
- Docs: update api-http.md, protocol.md with correct endpoints
- OpenAPI spec updated to v1.1.6

Known limitation: DELETE /databases disabled due to ORC SIGSEGV
in LSMTree.close(). Use SQL DROP DATABASE instead.

docs/bg/api-http.md

@@ -5,7 +5,7 @@ JSON-базиран REST API за уеб приложения.
 ## Базов URL
 
 ```
-http://localhost:9470
+http://localhost:9912
 ```
 
 ## Endpoints
@@ -15,53 +15,7 @@ http://localhost:9470
 Health проверка:
 
 ```bash
-curl http://localhost:9470/health
-```
-
-### GET /ready
-
-Readiness проверка:
-
-```bash
-curl http://localhost:9470/ready
-```
-
-### POST /query
-
-Изпълнение на BaraQL заявка:
-
-```bash
-curl -X POST http://localhost:9470/api/query \
-  -H "Content-Type: application/json" \
-  -d '{"query": "SELECT * FROM users WHERE age > 18"}'
-```
-
-Отговор:
-```json
-{
-  "columns": ["name", "age"],
-  "rows": [["Alice", 30], ["Bob", 25]],
-  "row_count": 2,
-  "duration_ms": 12
-}
-```
-
-### POST /batch
-
-Групови заявки:
-
-```bash
-curl -X POST http://localhost:9470/api/batch \
-  -H "Content-Type: application/json" \
-  -d '{"queries": ["INSERT users { name := \"Alice\" }", "INSERT users { name := \"Bob\" }"]}'
-```
-
-### GET /schema
-
-Преглед на схемата:
-
-```bash
-curl http://localhost:9470/api/schema
+curl http://localhost:9912/health
 ```
 
 ### GET /metrics
@@ -69,37 +23,110 @@ curl http://localhost:9470/api/schema
 Prometheus метрики:
 
 ```bash
-curl http://localhost:9470/metrics
+curl http://localhost:9912/metrics
 ```
 
-### POST /explain
+### POST /auth
 
-Обяснение на план за изпълнение:
+JWT автентикация:
 
 ```bash
-curl -X POST http://localhost:9470/api/explain \
+curl -X POST http://localhost:9912/auth \
   -H "Content-Type: application/json" \
+  -d '{"username": "admin", "password": "secret"}'
+```
+
+### POST /query
+
+Изпълнение на SQL заявка:
+
+```bash
+curl -X POST http://localhost:9912/query \
+  -H "Content-Type: application/json" \
+  -H "X-Database: default" \
   -d '{"query": "SELECT * FROM users WHERE age > 18"}'
 ```
 
+Отговор:
+```json
+{
+  "columns": ["name", "age"],
+  "rows": [{"name": "Alice", "age": 30}],
+  "affectedRows": 0
+}
+```
+
+> **Забележка:** Header `X-Database` избира към коя база данни да се изпълни заявката. Ако липсва, се използва `default`.
+
+### GET /tables
+
+Списък с таблици в избраната база данни:
+
+```bash
+curl http://localhost:9912/tables -H "X-Database: default"
+```
+
+### GET /databases
+
+Списък с налични бази данни:
+
+```bash
+curl http://localhost:9912/databases
+```
+
+### POST /databases
+
+Създаване на нова база данни (изисква admin права):
+
+```bash
+curl -X POST http://localhost:9912/databases \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer <token>" \
+  -d '{"name": "mydb"}'
+```
+
 ### POST /backup
 
-Създаване на backup:
+Създаване на backup (изисква admin права):
 
 ```bash
-curl -X POST http://localhost:9470/api/backup \
+# Backup на всички бази данни
+curl -X POST http://localhost:9912/backup \
   -H "Content-Type: application/json" \
-  -d '{"destination": "/backup/snapshot.db"}'
+  -H "Authorization: Bearer <token>" \
+  -d '{"all": true}'
+
+# Backup на единична база
+curl -X POST http://localhost:9912/backup \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer <token>" \
+  -d '{"database": "default"}'
+```
+
+### GET /backups
+
+Списък с налични архиви:
+
+```bash
+curl http://localhost:9912/backups -H "Authorization: Bearer <token>"
+```
+
+### POST /restore
+
+Възстановяване от архив (изисква admin права):
+
+```bash
+curl -X POST http://localhost:9912/restore \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer <token>" \
+  -d '{"input": "backup_1234567890.tar.gz", "all": true}'
 ```
 
 ## Грешки
 
 ```json
 {
-  "error": {
-    "code": "INVALID_QUERY",
-    "message": "Грешка в синтаксиса"
-  }
+  "error": "Unauthorized"
 }
 ```
 
@@ -107,5 +134,5 @@ curl -X POST http://localhost:9470/api/backup \
 
 ```bash
 curl -H "Authorization: Bearer <token>" \
-  http://localhost:9470/api/users
+  http://localhost:9912/metrics
 ```

docs/bg/protocol.md

@@ -240,9 +240,19 @@ Content-Type: application/json
 ```http
 POST /backup
 Content-Type: application/json
+Authorization: Bearer <token>
 
 {
-  "destination": "/backup/snapshot.db"
+  "all": true
+}
+```
+
+Отговор:
+```json
+{
+  "success": true,
+  "output": "backup_1234567890.tar.gz",
+  "message": "Backup created"
 }
 ```