kin: KIN-OBS-022 Исправить мелкие баги отображения и deprecation в cli/watch.py

core/db.py

@@ -737,6 +737,35 @@ def _migrate(conn: sqlite3.Connection):
             )
             conn.commit()
 
+    # Add UNIQUE(from_project, to_project, type) to project_links (KIN-INFRA-013).
+    # SQLite does not support ALTER TABLE ADD CONSTRAINT — table recreation required.
+    if "project_links" in existing_tables:
+        pl_sql_row = conn.execute(
+            "SELECT sql FROM sqlite_master WHERE type='table' AND name='project_links'"
+        ).fetchone()
+        pl_has_unique = pl_sql_row and "UNIQUE" in (pl_sql_row[0] or "").upper()
+        if not pl_has_unique:
+            conn.executescript("""
+                PRAGMA foreign_keys=OFF;
+                CREATE TABLE project_links_new (
+                    id INTEGER PRIMARY KEY AUTOINCREMENT,
+                    from_project TEXT NOT NULL REFERENCES projects(id),
+                    to_project TEXT NOT NULL REFERENCES projects(id),
+                    type TEXT NOT NULL,
+                    description TEXT,
+                    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+                    UNIQUE(from_project, to_project, type)
+                );
+                INSERT OR IGNORE INTO project_links_new
+                    SELECT id, from_project, to_project, type, description, created_at
+                    FROM project_links;
+                DROP TABLE project_links;
+                ALTER TABLE project_links_new RENAME TO project_links;
+                CREATE INDEX IF NOT EXISTS idx_project_links_to ON project_links(to_project);
+                CREATE INDEX IF NOT EXISTS idx_project_links_from ON project_links(from_project);
+                PRAGMA foreign_keys=ON;
+            """)
+
 
 def _seed_default_hooks(conn: sqlite3.Connection):
     """Seed default hooks for the kin project (idempotent).