step 7: actions — table, service, CLI, GUI tab + confirm dialog

- Migration 005: actions table (node_id, title, kind, command, args_json,
  working_dir, url, confirm_required, capture_output)
- ActionService: Create, Get, ListByNode, Delete, Run
  Run dispatches: open_url/file/folder (xdg-open), run_command/script
  (exec.Command), open_terminal, launch_app
- CLI: verstak action add/list/run/delete
  'run' shows confirm prompt for confirm_required actions
- GUI 'Действия' tab: button list with kind label, confirm_required
  opens editor overlay with action info + confirm, delete button
- 7 unit tests for ActionService

Acceptance: go build ./... pass, go test ./... pass.

internal/core/storage/migrations_005.sql.go

@@ -0,0 +1,21 @@
+package storage
+
+// migration005 — actions table for runnable actions attached to nodes.
+const migration005 = `
+CREATE TABLE IF NOT EXISTS actions (
+    id TEXT PRIMARY KEY,
+    node_id TEXT NOT NULL REFERENCES nodes(id),
+    title TEXT NOT NULL,
+    kind TEXT NOT NULL,
+    command TEXT NULL,
+    args_json TEXT NULL,
+    working_dir TEXT NULL,
+    url TEXT NULL,
+    confirm_required INTEGER NOT NULL DEFAULT 0,
+    capture_output INTEGER NOT NULL DEFAULT 0,
+    created_at TEXT NOT NULL,
+    updated_at TEXT NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_actions_node ON actions(node_id);
+`

internal/core/storage/storage.go

@@ -61,7 +61,8 @@ var migrationFiles = map[int]string{
 	2: migration002,
 	3: migration003,
 	4: migration004,
-	// 5: migration005, etc.
+	5: migration005,
+	// 6: migration006, etc.
 }
 
 func (db *DB) runInitialSchema() error {