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/src/manifest.ts

@@ -35,6 +35,8 @@ export function generateManifest(baseUrl = '/api/mizan'): EdgeManifest {
                 fnEntry.methods = entry.methods || ['GET']
                 pageRoutes.push(entry.route)
             }
+            if (entry.rev !== undefined && entry.rev !== 0) fnEntry.rev = entry.rev
+            if (entry.cache !== undefined && entry.cache !== true) fnEntry.cache = entry.cache
             functions.push(fnEntry)
         }