feat: add support for stat templates

Introduces a new `template` stat type that allows for table-based
lookups via CSV blocks in markdown files. When a template stat is
rolled, it uses a dice expression defined in the template to select
an entry, applies a label, and automatically updates associated
modifier stats using relative values.

src/cli/commands/serve.ts

@@ -272,13 +272,14 @@ export function createContentServer(
     links: [],
     sparkTables: [],
     stats: [],
+    statTemplates: [],
   };
 
   /** Re-scan completions from current content index (cached) */
   function recomputeCompletions(): void {
     completionsIndex = scanCompletions(contentIndex);
     console.log(
-      `[completions] dice=${completionsIndex.dice.length} links=${completionsIndex.links.length} sparkTables=${completionsIndex.sparkTables.length} stats=${completionsIndex.stats.length}`,
+      `[completions] dice=${completionsIndex.dice.length} links=${completionsIndex.links.length} sparkTables=${completionsIndex.sparkTables.length} stats=${completionsIndex.stats.length} templates=${completionsIndex.statTemplates.length}`,
     );
   }