refactor: replace stat-parser with declare-parser

Replace the old stat-parser logic with a new declare-parser to handle
variable declarations and tag modifiers. This includes moving the
declare-parser logic to a shared location in cli/completions to avoid
duplication between the CLI and the journal component.

src/cli/completions/declare-parser.ts

@@ -0,0 +1,116 @@
+/**
+ * Declare parser — parses ```csv role=declare code blocks from markdown.
+ *
+ * Shared between CLI completions scanner and browser-side completions.
+ *
+ * Format:
+ *   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
+ *
+ * When `tag` is empty: $key is a reactively computed variable.
+ * When `tag` is present: when #tag is active, $key gets expr added to its base.
+ */
+
+export interface VarDeclaration {
+  key: string;        // "$hp" (always starts with $)
+  expression: string; // "$con*5+$mod_hp"
+}
+
+export interface TagModifier {
+  tag: string;        // "#warrior"
+  target: string;     // "$mod_hp"
+  expression: string; // "20"
+}
+
+export interface DeclareResult {
+  variables: VarDeclaration[];
+  tagModifiers: TagModifier[];
+}
+
+/**
+ * Parse a ```csv role=declare block.
+ */
+export function parseDeclareCsv(csv: string, source: string): DeclareResult {
+  const lines = csv.trim().split(/\r?\n/);
+  if (lines.length === 0) return { variables: [], tagModifiers: [] };
+
+  // First line is header; validate it
+  const headers = lines[0].split(",").map((h) => h.trim().toLowerCase());
+  if (headers[0] !== "tag" || headers[1] !== "key" || headers[2] !== "expr") {
+    throw new Error(
+      `${source}: role=declare blocks must have headers "tag,key,expr". Got: ${headers.join(",")}`,
+    );
+  }
+
+  const variables: VarDeclaration[] = [];
+  const tagModifiers: TagModifier[] = [];
+
+  for (let i = 1; i < lines.length; i++) {
+    const row = lines[i].trim();
+    if (!row || row.startsWith("#")) continue;
+
+    const cols = splitCsvRow(row);
+    if (cols.length < 3) continue;
+
+    const tag = cols[0]?.trim() ?? "";
+    const key = cols[1]?.trim() ?? "";
+    const expr = cols[2]?.trim() ?? "";
+
+    if (!key || !expr) {
+      console.warn(`${source}:${i + 1}: skipping row with empty key or expr`);
+      continue;
+    }
+
+    if (tag) {
+      // Tag modifier
+      if (!tag.startsWith("#")) {
+        throw new Error(
+          `${source}:${i + 1}: tag must start with #, got "${tag}"`,
+        );
+      }
+      if (!key.startsWith("$")) {
+        throw new Error(
+          `${source}:${i + 1}: key must start with $, got "${key}"`,
+        );
+      }
+      tagModifiers.push({ tag, target: key, expression: expr });
+    } else {
+      // Variable declaration
+      if (!key.startsWith("$")) {
+        throw new Error(
+          `${source}:${i + 1}: key must start with $, got "${key}"`,
+        );
+      }
+      variables.push({ key, expression: expr });
+    }
+  }
+
+  return { variables, tagModifiers };
+}
+
+// ---------------------------------------------------------------------------
+// CSV row splitter
+// ---------------------------------------------------------------------------
+
+function splitCsvRow(row: string): string[] {
+  const cols: string[] = [];
+  let current = "";
+  let inQuote = false;
+
+  for (let i = 0; i < row.length; i++) {
+    const ch = row[i];
+    if (ch === '"') {
+      inQuote = !inQuote;
+    } else if (ch === "," && !inQuote) {
+      cols.push(current);
+      current = "";
+    } else {
+      current += ch;
+    }
+  }
+  cols.push(current);
+  return cols;
+}