feat: add threshold support and tagmap support to variable system

Introduce a `threshold` column to tag modifiers in CSV declarations,
allowing modifiers to activate only when a tag's count meets a minimum
requirement.

Implement support for "tagmap" variables (e.g., `#warrior:1;#druid:2`)
which allow for complex, multi-tag state tracking. These variables
can receive specialized tagmap modifications rather than simple
numeric additions.

src/cli/completions/declare-parser.ts

@@ -3,15 +3,16 @@
  *
  * Shared between CLI completions scanner and browser-side completions.
  *
- * Format (columns can be in any order; `tag` is optional):
- *   tag,key,expr
- *   ,$hp,$con*5+$mod_hp          ← variable declaration
- *   ,$ac,10+$dex                   ← variable declaration
- *   #warrior,$mod_hp,20           ← tag modifier
- *   #warrior,$mod_str,1           ← tag modifier
+ * Format (columns can be in any order; `tag` and `threshold` are optional):
+ *   tag,threshold,key,expr
+ *   ,,$hp,$con*5+$mod_hp          ← variable declaration
+ *   ,,$ac,10+$dex                   ← variable declaration
+ *   #warrior,2,$mod_hp,20           ← tag modifier (threshold 2)
+ *   #warrior,,$mod_str,1            ← tag modifier (threshold defaults to 1)
  *
  * When `tag` is empty: $key is a reactively computed variable.
- * When `tag` is present: when #tag is active, $key gets expr added to its base.
+ * When `tag` is present: when #tag met (source's tagmap value >= threshold),
+ *   $key gets expr added to its base.
  */
 
 import { parse } from "csv-parse/browser/esm/sync";
@@ -57,6 +58,7 @@ export interface TagModifier {
   tag: string;        // "#warrior"
   target: string;     // "$mod_hp"
   expression: string; // "20"
+  threshold: number;  // minimum tagmap count to activate (default 1)
 }
 
 export interface DeclareResult {
@@ -84,7 +86,7 @@ export function parseDeclareCsv(csv: string, source: string): DeclareResult {
     columns: true,
     trim: true,
     skipEmptyLines: true,
-  }) as Array<{ tag?: string; key: string; expr: string }>;
+  }) as Array<{ tag?: string; threshold?: string; key: string; expr: string }>;
 
   const variables: VarDeclaration[] = [];
   const tagModifiers: TagModifier[] = [];
@@ -111,7 +113,14 @@ export function parseDeclareCsv(csv: string, source: string): DeclareResult {
           `${source}: key must start with $, got "${key}"`,
         );
       }
-      tagModifiers.push({ tag, target: key, expression: expr });
+      const thresholdRaw = row.threshold?.trim() ?? "";
+      const threshold = thresholdRaw ? parseInt(thresholdRaw, 10) : 1;
+      if (isNaN(threshold) || threshold < 1) {
+        throw new Error(
+          `${source}: threshold must be a positive integer, got "${row.threshold}"`,
+        );
+      }
+      tagModifiers.push({ tag, target: key, expression: expr, threshold });
     } else {
       // Variable declaration
       if (!key.startsWith("$")) {