chore add core rust project files and diesel migrations

Track required workspace crates, scripts, and historical diesel migrations so the repository contains the complete runnable backend baseline.

Made-with: Cursor

htyts_models/migrations/2026-03-22-120000_create_dbtask/down.sql

@@ -0,0 +1 @@
+DROP TABLE IF EXISTS dbtask;

htyts_models/migrations/2026-03-22-120000_create_dbtask/up.sql

@@ -0,0 +1,14 @@
+-- Hibernate `DbTask` → table `dbtask` (Java task_commons / task_server).
+
+CREATE TABLE dbtask (
+    task_id TEXT PRIMARY KEY,
+    hty_id TEXT,
+    task_type TEXT NOT NULL,
+    task_status TEXT NOT NULL,
+    duration DOUBLE PRECISION,
+    created_by TEXT NOT NULL,
+    created_at TIMESTAMP NOT NULL,
+    updated_by TEXT NOT NULL,
+    updated_at TIMESTAMP NOT NULL,
+    meta TEXT
+);