init v.1.0.0

Co-authored-by: Copilot <copilot@github.com>

architecture.mmd

@@ -0,0 +1,93 @@
+%% dvd-thing — ports and adapters.
+%% Every dependency arrow points inward. domain knows nothing; application knows
+%% only domain; adapters know both but are known by neither.
+flowchart TB
+    subgraph root["bin — composition root"]
+        main["main.rs<br/><i>the only place that names Wayland</i>"]
+    end
+
+    subgraph adapters["adapters — std"]
+        direction LR
+
+        subgraph wayland["wayland"]
+            display["WaylandDisplay<br/><i>layer-shell surface, frame pacing, signals</i>"]
+            renderer["SoftwareRenderer<br/><i>double-buffered shm, damage tracking</i>"]
+            logoimage["LogoImage<br/><i>decode, scale, tint cache</i>"]
+            state["WaylandState<br/><i>protocol dispatch</i>"]
+        end
+
+        subgraph assets["assets"]
+            filesource["FileLogoSource<br/><i>$DVD_LOGO, XDG / macOS / Windows</i>"]
+        end
+    end
+
+    subgraph app["application — no_std, no alloc"]
+        direction LR
+
+        subgraph portsgroup["ports"]
+            displayport["DisplayOverlayPort<br/><i>screen_dimensions, wait_for_frame</i>"]
+            rendererport["RendererPort<br/><i>render_frame</i>"]
+            logoport["LogoSourcePort<br/><i>load</i>"]
+        end
+
+        usecases["use_cases<br/><b>run</b> · blocking loop<br/><b>step</b> · one frame, for callback platforms"]
+        apperror["ApplicationError<br/><i>heapless Message, 108 bytes</i>"]
+    end
+
+    subgraph dom["domain — no_std, no alloc"]
+        direction LR
+
+        scene["ScreensaverScene<br/><b>aggregate root</b><br/><i>sole entry point: tick, sprites</i>"]
+        logo["BouncingLogo<br/><i>pub(crate)</i>"]
+        sparkle["Sparkle<br/><i>pub(crate)</i>"]
+        sprite["Sprite + SpriteKind<br/><i>what to draw, not how</i>"]
+        vo["Value objects<br/>Point2D · Vector2D<br/>Dimensions · Color<br/><i>self-validating, const fn</i>"]
+        domerror["DomainError<br/><i>InvalidDimensions</i>"]
+    end
+
+    main --> usecases
+    main --> scene
+    main -.->|constructs| display
+    main -.->|constructs| renderer
+    main -.->|constructs| filesource
+
+    usecases --> displayport
+    usecases --> rendererport
+    usecases --> scene
+
+    display -.->|implements| displayport
+    renderer -.->|implements| rendererport
+    filesource -.->|implements| logoport
+
+    renderer -->|"sprites()"| scene
+    renderer --> logoimage
+    logoimage -->|"load()"| logoport
+    renderer --> display
+    display --> state
+
+    scene -->|owns| logo
+    scene -->|"owns [Option Sparkle; 108]"| sparkle
+    logo --> sprite
+    sparkle --> sprite
+    sprite --> vo
+    scene --> vo
+    scene -.->|"new() rejects"| domerror
+    apperror -.->|wraps| domerror
+
+    classDef domainStyle fill:#1f4e3d,stroke:#41b883,color:#e8f5ee
+    classDef appStyle fill:#1e3a5f,stroke:#4a9eff,color:#e6f0ff
+    classDef adapterStyle fill:#4a3410,stroke:#d99a2b,color:#fdf3e0
+    classDef rootStyle fill:#3d2645,stroke:#b06fc9,color:#f6ecfa
+
+    style root fill:#88888810,stroke:#9a9a9a
+    style adapters fill:#88888810,stroke:#9a9a9a
+    style wayland fill:#88888810,stroke:#9a9a9a
+    style assets fill:#88888810,stroke:#9a9a9a
+    style app fill:#88888810,stroke:#9a9a9a
+    style portsgroup fill:#88888810,stroke:#9a9a9a
+    style dom fill:#88888810,stroke:#9a9a9a
+
+    class scene,logo,sparkle,sprite,vo,domerror domainStyle
+    class displayport,rendererport,logoport,usecases,apperror appStyle
+    class display,renderer,logoimage,state,filesource adapterStyle
+    class main rootStyle