Add rev and cache parameters to @client decorator

rev=N: bumped by developer when function logic changes. Becomes part of
the HMAC cache key — old cache entries are unreachable without purge.
Effective rev for a context is max(rev) across all functions in it.

cache=int|False|True: TTL escape hatch for unobservable mutations.
cache=60 emits s-maxage=60. cache=False emits no-store. Default (True)
emits s-maxage=31536000 (forever, purge on mutation).
Effective cache for a context is min(TTL) across functions, with False
taking precedence.

Both parameters flow through: decorator → meta → manifest → cache key
and Cache-Control headers. Implemented in both Python and TypeScript
with 13 Python tests and 4 TypeScript tests.

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

packages/mizan-ts/tests/edge-compat.test.ts

@@ -228,4 +228,50 @@ describe('Manifest', () => {
         expect(m.mutations.stripeWebhook.route).toBe('/webhooks/stripe/')
         expect(m.mutations.stripeWebhook.methods).toEqual(['POST'])
     })
+
+    test('rev appears in manifest', () => {
+        clearRegistry()
+        const Ctx = new ReactContext('data')
+        client({ context: Ctx, rev: 3 }, async function versionedFn(itemId: number) {
+            return { value: itemId }
+        })
+
+        const m = generateManifest()
+        const fn = m.contexts.data.functions[0]
+        expect(fn.rev).toBe(3)
+    })
+
+    test('cache TTL appears in manifest', () => {
+        clearRegistry()
+        const Ctx = new ReactContext('trending')
+        client({ context: Ctx, cache: 60 }, async function trendingFn() {
+            return { items: [] }
+        })
+
+        const m = generateManifest()
+        const fn = m.contexts.trending.functions[0]
+        expect(fn.cache).toBe(60)
+    })
+
+    test('cache=60 sets s-maxage=60', async () => {
+        clearRegistry()
+        const Ctx = new ReactContext('live')
+        client({ context: Ctx, cache: 60 }, async function liveFn() {
+            return { score: 42 }
+        })
+
+        const r = await handleContextFetch('live', {})
+        expect(r.headers['Cache-Control']).toBe('public, max-age=0, s-maxage=60')
+    })
+
+    test('cache=false sets no-store', async () => {
+        clearRegistry()
+        const Ctx = new ReactContext('random')
+        client({ context: Ctx, cache: false }, async function randomFn() {
+            return { value: Math.random() }
+        })
+
+        const r = await handleContextFetch('random', {})
+        expect(r.headers['Cache-Control']).toBe('no-store')
+    })
 })