chore: P0 skeleton

Bootstrap the Dashward repo per arch/UBUNTU-DASHBOARD-SPACE.md:

- pnpm-workspaces monorepo (sdk, extension, container, widgets-builtin/*)
- GNOME extension stub (metadata.json, src/*.ts placeholders for warden,
  guard, supervisor, entry UX, DBus service)
- WebKit container stub (GJS main + page-side runtime + dashboard.html)
- TypeScript widget SDK (defineWidget + types)
- Builtin clock widget as the first SDK consumer example
- DBus interface XML (proto/shell.iface.xml) and shared types
- esbuild configs for extension and container; tsc for SDK
- Design doc copied in at repo root for discoverability

No functional logic yet -- all components are placeholders that compose
in extension.ts so the build chain can be exercised. P1 (workspace
warden) starts next.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -0,0 +1,60 @@
+# Dashward
+
+A dedicated rightmost workspace for custom widgets on Ubuntu/GNOME, in the
+spirit of macOS Dashboard.
+
+- **GNOME Shell extension** (GJS) creates the dashboard workspace, defends
+  it from regular window incursions, and supervises the container.
+- **WebKitGTK container** (separate process) renders an HTML page on that
+  workspace.
+- **Widget SDK** (TypeScript) lets you write widgets as web components.
+
+Status: P0 skeleton. Design lives in
+[`UBUNTU-DASHBOARD-SPACE.md`](https://git.hangman-lab.top/hzhang/Dashward/src/branch/main/UBUNTU-DASHBOARD-SPACE.md)
+(see also `~/arch/UBUNTU-DASHBOARD-SPACE.md` locally).
+
+## Target
+
+- Ubuntu 25.04 / GNOME Shell 48 / Wayland.
+- Other distros & versions: post-v1.
+
+## Repo layout
+
+```
+sdk/                      TS widget SDK, published as @dashward/widget-sdk
+extension/                GNOME Shell extension (GJS, TS-authored)
+  src/                    Extension source
+  widgets-builtin/        Builtin widgets shipped with the extension
+container/                WebKit kiosk process
+  src/                    GJS bootstrap
+  runtime/                Page-side runtime (host grid, edit mode, widget loader)
+widgets/                  Example / 3rd-party widget dev tree
+proto/                    Shared DBus XML + TS types
+scripts/                  Build & dev helpers
+```
+
+## Dev setup
+
+Requires Node ≥ 20 and pnpm ≥ 9. To install pnpm:
+
+```bash
+npm install -g pnpm
+```
+
+Then:
+
+```bash
+pnpm install
+pnpm build
+```
+
+## Testing discipline
+
+All Shell-side iteration happens inside the
+`ubuntu2504-test` libvirt VM, **never on the host GNOME session** — a
+buggy extension can lock you out of the Wayland session. See the design
+doc §17 for the dev loop.
+
+## License
+
+TBD.