review fixes: light-mode contrast, tz robustness, deploy copy

- admin: maroon buttons use .danger class (white text); replace hardcoded
  #333/#ff8a8a/drop-target colors with theme vars so light mode is legible
- time.ts: force hourCycle h23 (no 24:00 artifact), drop dead 24-guard
- Makefile/README: rsync with excludes instead of `cp -a .` so .git and the
  dev DB don't ship to /opt; add rsync to deps

server/src/time.ts

@@ -39,7 +39,7 @@ function localParts(d: Date, tz: string = TZ): LocalParts {
     hour: '2-digit',
     minute: '2-digit',
     second: '2-digit',
-    hour12: false,
+    hourCycle: 'h23', // force midnight as 00, never the 24 artifact
   });
   const parts: Record<string, string> = {};
   for (const p of fmt.formatToParts(d)) {
@@ -49,7 +49,7 @@ function localParts(d: Date, tz: string = TZ): LocalParts {
     year: Number(parts.year),
     month: Number(parts.month),
     day: Number(parts.day),
-    hour: Number(parts.hour === '24' ? '0' : parts.hour),
+    hour: Number(parts.hour),
     minute: Number(parts.minute),
     second: Number(parts.second),
   };