refactor(md-deck): pos string and yaml copy output

Replace per-axis x1/y1/x2/y2 layer fields with a single
pos string (x1,y1-x2,y2) matching the compact layers format.

When a deck is configured via a yaml/tag codeblock (data-config),
the copy button now emits a yaml/tag block serialized from current
store state so template layers round-trip.

src/components/md-deck/hooks/deckStore.ts

@@ -1,4 +1,5 @@
 import { createStore } from "solid-js/store";
+import yaml from "js-yaml";
 import { calculateDimensions } from "./dimensions";
 import { loadCSV, CSV } from "../../utils/csv-loader";
 import { formatLayers } from "./layer-parser";
@@ -41,6 +42,8 @@ export interface DeckState {
   cornerRadius: number;
   shape: CardShape;
   fixed: boolean;
+  /** True when the deck was configured via a yaml/tag codeblock (data-config). */
+  isYamlBlock: boolean;
   src: string;
   rawSrc: string;
 
@@ -85,6 +88,7 @@ export interface DeckActions {
   setPadding: (padding: number) => void;
   setCornerRadius: (cornerRadius: number) => void;
   setShape: (shape: CardShape) => void;
+  setIsYamlBlock: (isYamlBlock: boolean) => void;
 
   setCards: (cards: CSV<CardData>) => void;
   setActiveTab: (index: number) => void;
@@ -176,6 +180,7 @@ export function createDeckStore(initialSrc: string = ""): DeckStore {
     cornerRadius: DECK_DEFAULTS.CORNER_RADIUS,
     shape: "rectangle",
     fixed: false,
+    isYamlBlock: false,
     src: initialSrc,
     rawSrc: initialSrc,
     dimensions: null,
@@ -244,6 +249,9 @@ export function createDeckStore(initialSrc: string = ""): DeckStore {
   const setShape = (shape: CardShape) => {
     setState({ shape });
   };
+  const setIsYamlBlock = (isYamlBlock: boolean) => {
+    setState({ isYamlBlock });
+  };
 
   const setCards = (cards: CSV<CardData>) => setState({ cards, activeTab: 0 });
   const setActiveTab = (index: number) => setState({ activeTab: index });
@@ -483,6 +491,9 @@ export function createDeckStore(initialSrc: string = ""): DeckStore {
   const clearError = () => setState({ error: null });
 
   const generateCode = (backLayersStr?: string) => {
+    if (state.isYamlBlock) {
+      return generateYamlCode();
+    }
     const frontLayersStr = formatLayers(state.frontLayerConfigs);
     const backLayersString =
       backLayersStr || formatLayers(state.backLayerConfigs);
@@ -510,6 +521,49 @@ export function createDeckStore(initialSrc: string = ""): DeckStore {
     return parts.join("");
   };
 
+  /** Serialize the deck back to a ```yaml/tag codeblock (round-trips templates). */
+  const generateYamlCode = () => {
+    const toYamlLayer = (l: LayerConfig) => {
+      const out: Record<string, unknown> = {};
+      if (l.template) {
+        out.template = l.template;
+      } else {
+        out.prop = l.prop ?? "";
+      }
+      out.pos = `${l.x1},${l.y1}-${l.x2},${l.y2}`;
+      if (l.fontSize) out.font = l.fontSize;
+      if (l.orientation && l.orientation !== "n") out.orientation = l.orientation;
+      if (l.align) out.align = l.align;
+      if (!l.visible) out.visible = false;
+      return out;
+    };
+
+    const config: Record<string, unknown> = {
+      size: `${state.sizeW}x${state.sizeH}`,
+      grid: `${state.gridW}x${state.gridH}`,
+      layers: state.frontLayerConfigs.map(toYamlLayer),
+    };
+    if (state.bleed !== DECK_DEFAULTS.BLEED) config.bleed = state.bleed;
+    if (state.padding !== DECK_DEFAULTS.PADDING) config.padding = state.padding;
+    if (state.shape !== "rectangle") config.shape = state.shape;
+    if (state.backLayerConfigs.length > 0) {
+      config.back_layers = state.backLayerConfigs.map(toYamlLayer);
+    }
+
+    const doc = {
+      tag: "md-deck",
+      body: state.rawSrc || state.src,
+      "data-config": config,
+    };
+    const yamlStr = yaml.dump(doc, {
+      indent: 2,
+      lineWidth: -1,
+      noRefs: true,
+    });
+    const fence = "```";
+    return `${fence}yaml/tag\n${yamlStr}${fence}`;
+  };
+
   const copyCode = async (fallback?: (code: string) => void) => {
     const code = generateCode();
     try {
@@ -569,6 +623,7 @@ export function createDeckStore(initialSrc: string = ""): DeckStore {
     setPadding,
     setCornerRadius,
     setShape,
+    setIsYamlBlock,
     setCards,
     setActiveTab,
     updateCardData,