feat(journal): support <tspan> in stat sheet templates

Update the stat sheet parser to scan <tspan> elements within <text>
nodes. This allows for individual binding of template patterns to
specific tspans, preserving their position attributes.

src/components/journal/stat-sheet.ts

@@ -1,18 +1,22 @@
 /**
  * Stat sheet template engine — parses *.sheet.svg files and extracts
- * <text> elements containing ${key} template patterns.
+ * text nodes containing ${key} template patterns.
  *
- * The SVG element is parsed once via DOMParser. The caller (StatsView)
- * reactively updates the text nodes whenever the stats store changes.
+ * Walks <text> elements. If a <text> has <tspan> children, we bind to
+ * each <tspan> individually (preserving their position attributes).
+ * If a <text> has no <tspan> children, we bind to the <text> directly.
  */
 
 /** Regex matching ${key} template patterns (captures the key name). */
 const TEMPLATE_RE = /\$\{(\w+)\}/g;
 
-/** A single template binding in a <text> element. */
+/** A single template binding targeting a specific text-bearing leaf node. */
 export interface TextTemplate {
-  el: SVGTextElement;
+  /** The DOM node to update — a <text> (no children) or a <tspan>. */
+  el: SVGTextContentElement;
+  /** Original text content with ${key} placeholders. */
   template: string;
+  /** Bare key names extracted from the template. */
   keys: string[];
 }
 
@@ -23,8 +27,32 @@ export interface ParsedSheet {
 }
 
 /**
- * Parse an SVG string into a live DOM element and extract all text
- * elements that contain ${key} template patterns.
+ * Check if a text node's content has template patterns, and if so,
+ * register a binding.
+ */
+function scanNode(el: Element, templates: TextTemplate[]): void {
+  const content = el.textContent;
+  if (!content) return;
+
+  TEMPLATE_RE.lastIndex = 0;
+  const keys: string[] = [];
+  let m: RegExpExecArray | null;
+  while ((m = TEMPLATE_RE.exec(content)) !== null) {
+    keys.push(m[1]);
+  }
+
+  if (keys.length > 0) {
+    templates.push({
+      el: el as SVGTextContentElement,
+      template: content,
+      keys,
+    });
+  }
+}
+
+/**
+ * Parse an SVG string into a live DOM element and extract all template
+ * bindings from <text> and <tspan> leaf nodes.
  */
 export function parseSheet(svgString: string): ParsedSheet {
   const parser = new DOMParser();
@@ -42,21 +70,18 @@ export function parseSheet(svgString: string): ParsedSheet {
   }
 
   const templates: TextTemplate[] = [];
-  const textEls = svgElement.querySelectorAll("text");
 
-  for (const el of textEls) {
-    const content = el.textContent;
-    if (!content) continue;
+  for (const textEl of svgElement.querySelectorAll("text")) {
+    const tspans = textEl.querySelectorAll("tspan");
 
-    TEMPLATE_RE.lastIndex = 0;
-    const keys: string[] = [];
-    let m: RegExpExecArray | null;
-    while ((m = TEMPLATE_RE.exec(content)) !== null) {
-      keys.push(m[1]);
+    if (tspans.length > 0) {
+      // Has children — bind to each <tspan> individually
+      for (const tspan of tspans) {
+        scanNode(tspan, templates);
       }
-
-    if (keys.length > 0) {
-      templates.push({ el: el as SVGTextElement, template: content, keys });
+    } else {
+      // Leaf <text> — bind directly
+      scanNode(textEl, templates);
     }
   }