feat(vacay): comp/flex leave type (#1074) + configurable-year backend (#737)

Comp/Flex days (#1074) — complete. A second leave type that does not deduct from the vacation entitlement (flextime / overtime offset). New kind column on vacay_entries, excluded from usedDays via a CASE sum; toggleEntry carries kind through service/nest/store with change-detection; desktop and mobile get a comp toolbar toggle next to the half-day one (orthogonal, so a half comp day is free); comp segments render as a diagonal hatch of the person colour, per-segment for split days (Version B). comp_used is surfaced separately in getStats. Translated into all 23 locales.

Configurable vacation year (#737) — backend only. Per-user vacay_user_settings (calendar / fiscal / anniversary), resolveYearWindow, and usedDays / compUsedDays / getStats / carry-over now computed over the leave-year [start,end) window. 'calendar' resolves byte-identically to the old date-prefix behaviour, so nothing changes for existing users and the feature is inert until the settings UI lands. Frontend (settings selector + calendar window rollover), the settings endpoint, window-aware getEntries and holiday loading are still to do — see the PR description.

server/src/mcp/tools/vacay.ts

@@ -254,7 +254,7 @@ export function registerVacayTools(server: McpServer, userId: number, scopes: st
       async ({ date }) => {
         if (isDemoUser(userId)) return demoDenied();
         const planId = getActivePlanId(userId);
-        const result = toggleEntry(userId, planId, date, 1, undefined);
+        const result = toggleEntry(userId, planId, date, 1, 'vacation', undefined);
         return ok(result);
       }
     );