refactor(agents): share leadership role detector, use word-boundary match

P2-23: 'lead' in system-prompt.ts matched 'cleaner' / 'leaderboard' via
substring .includes(). Hoist LEADERSHIP_ROLE_KEYWORDS into a shared
agent-role-helpers.ts module; tokenize input on non-alphanum to require
whole-word match.

P3-54: Same keyword list was duplicated in automation-skills with drift
(missing 'ceo', different members). Both sites now call through the
shared helper.

src/main/agent-role-helpers.ts

@@ -0,0 +1,33 @@
+/**
+ * Role-classification helpers used across prompt construction and skill
+ * auto-assignment. Keeping a single keyword list here prevents drift
+ * between system-prompt.ts and automation-skills.ts.
+ *
+ * Matching uses word-boundary tokenization instead of substring search,
+ * so "lead" does not match "cleaner" or "leaderboard".
+ */
+
+export const LEADERSHIP_ROLE_KEYWORDS = [
+  "chief",
+  "cto",
+  "cmo",
+  "coo",
+  "cfo",
+  "ceo",
+  "vp",
+  "vice",
+  "president",
+  "head",
+  "director",
+  "manager",
+  "lead",
+] as const;
+
+function tokenize(text: string): string[] {
+  return text.toLowerCase().match(/[a-z0-9]+/g) ?? [];
+}
+
+export function roleMatchesLeadershipKeywords(role: string, title?: string | null): boolean {
+  const tokens = new Set(tokenize(`${role} ${title ?? ""}`));
+  return LEADERSHIP_ROLE_KEYWORDS.some((keyword) => tokens.has(keyword));
+}