Remove CDN Cache-Control headers; fix cross-language sort bug

Mizan's protocol layers (origin Redis cache, Edge Worker) handle caching
autonomously. The origin emits Cache-Control: no-store on ALL responses —
browsers and non-Mizan intermediaries must not cache. The Edge Worker
controls CDN caching via cf object, independent of origin headers.

Also fixes:
- TS localeCompare → byte-order sort (localeCompare is locale-sensitive,
  would produce different HMAC keys for non-ASCII params vs Python)
- Python cache_purge: empty {} params no longer treated as falsy
  (was inconsistent with JS where {} is truthy)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/mizan-ts/src/cache/keys.ts

@@ -40,7 +40,7 @@ export function deriveCacheKey(
     rev: number = 0,
 ): string {
     const sortedParams: Record<string, string> = {}
-    for (const [k, v] of Object.entries(params).sort(([a], [b]) => a.localeCompare(b))) {
+    for (const [k, v] of Object.entries(params).sort(([a], [b]) => a < b ? -1 : a > b ? 1 : 0)) {
         sortedParams[k] = String(v)
     }