refactor: convert to bun-workspaces monorepo (desktop/ + www/)

- Move the Tauri app (React frontend + Rust backend) into desktop/ via
  git mv — configs unchanged (relative paths: tauri.conf.json, vite.config.ts)
- Root package.json becomes a private bun workspace container with
  orchestration scripts; desktop package renamed gridline-desktop
- Scaffold www/ with Astro 7 + Tailwind v4 (hand-wired vite plugin,
  static output, ready for Dokploy)
- Update release.yml for the new layout: projectPath: desktop,
  desktop/src-tauri resource paths, rust-cache workspace path
- Update README + AGENTS.md structure trees and dev commands
- Verified: vitest (1074), cargo test (354), desktop build, tauri dev
  (window launches), tauri build (dmg + app bundles), Astro build

desktop/src/components/connections/connectionFormData.ts

@@ -0,0 +1,27 @@
+import type { DbType } from "../../lib/types";
+import type { Environment } from "./EnvironmentSelect";
+
+export interface ConnectionFormData {
+  name: string;
+  environment: Environment;
+  folder_id: string | null;
+  tag_ids: string[];
+  connection_string: string;
+  db_type: DbType;
+  host: string;
+  port: number | null;
+  username: string | null;
+  password: string | null;
+  database: string | null;
+  use_keychain: boolean;
+  // SSH tunnel fields (non-secret flat fields are optional; SshFields writes
+  // the key path under ssh_private_key, which submit handlers map to
+  // ssh_private_key_path on ConnectionInput)
+  ssh_host?: string | null;
+  ssh_port?: number | null;
+  ssh_user?: string | null;
+  ssh_auth_method?: "password" | "key" | null;
+  ssh_private_key?: string | null;
+  ssh_password: string | null;
+  ssh_passphrase?: string | null;
+}