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/tests/edge-compat.test.ts

@@ -52,11 +52,9 @@ describe('Edge Compatibility', () => {
 
     // ── Cache-Control correctness ───────────────────────────────────────
 
-    test('context GET is cacheable', async () => {
+    test('context GET emits no-store', async () => {
         const r = await handleContextFetch('user', { userId: '5' })
-        expect(r.headers['Cache-Control']).toContain('public')
-        expect(r.headers['Cache-Control']).toContain('s-maxage')
-        expect(r.headers['Cache-Control']).not.toContain('no-store')
+        expect(r.headers['Cache-Control']).toBe('no-store')
     })
 
     test('mutation POST not cacheable', async () => {
@@ -253,7 +251,7 @@ describe('Manifest', () => {
         expect(fn.cache).toBe(60)
     })
 
-    test('cache=60 sets s-maxage=60', async () => {
+    test('cache=60 still emits no-store on HTTP', async () => {
         clearRegistry()
         const Ctx = new ReactContext('live')
         client({ context: Ctx, cache: 60 }, async function liveFn() {
@@ -261,7 +259,7 @@ describe('Manifest', () => {
         })
 
         const r = await handleContextFetch('live', {})
-        expect(r.headers['Cache-Control']).toBe('public, max-age=0, s-maxage=60')
+        expect(r.headers['Cache-Control']).toBe('no-store')
     })
 
     test('cache=false sets no-store', async () => {