A channel's message slots are named from the client, on every backend

The IR called them react-message and django-message, so a FastAPI channel had
to declare a DjangoMessage. They are client-message and server-message now,
and the direction words hold wherever a channel is declared: Params /
ClientMessage / ServerMessage, with mizan-core deriving <Pascal>Params and
friends so no backend names a type itself. Django's ReactChannel and
FastAPI's ReactChannel are both Channel.

mizan-fastapi never registered a channels extension, so build_ir() emitted no
channel at all and every payload type was invisible to codegen. It registers
one now. RegistryExtension is an ABC requiring all(), which is what the IR
reads — an extension that cannot enumerate its registrations no longer exists.

The gate that should have caught the rename could not: tests/afi registered no
channel because mizan-rust had no channel registry to register one in, so a
five-package rename of the wire contract passed byte-parity without a channel
byte crossing it. mizan-rust grows ChannelSlotKind, a CHANNELS slice, a
#[mizan::channel] macro, and KDL emission whose wire_to_pascal matches Python's
split; the AFI fixture now carries a channel with every slot and one with a
single slot, so all three backends prove the contract byte for byte.

MizanChannel held three Option<String> beside three has_*() predicates and
unwrapped them with defaults; it holds an ordered slot vector, so an absent
slot is absent rather than defaulted. The channels target emitted a React
hooks file that a stage1-only consumer could not compile — react emits that
now. The codegen's parity tests byte-compared emitted source against baselines
without ever compiling it: they compile the generated crate and run its tests,
import the generated Python package and call every method, and typecheck each
TypeScript target against a consumer.

Also fixed at source: app_visitor printed its import diagnostic to stdout, the
stream export_mizan_ir writes KDL to, so a failed import silently corrupted the
IR; the apps root was hardcoded to "apps"; _default_literal crashed build_ir on
any non-JSON-serializable field default; Django and mizan-core derived Pascal
names two different ways, disagreeing on every dotted channel name.

ir.py builds a document and renders templates/ir/document.kdl.j2 rather than
appending KDL strings with hand-tracked indentation, and named types resolve to
a fixed point — a model reachable only through a union branch was referenced by
a ref that no type block ever defined.

The rest is the write-gate's own classifiers run over the standing tree:
relative imports, silent swallows, Protocol contracts that should be ABCs,
emitters hand-rendering target source, catch-all arms over closed enums, and
comments narrating the project rather than the code.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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

@@ -1,25 +1,18 @@
-/**
- * Edge Compatibility Tests — mirrors Django's EdgeCompatibilityTests exactly.
- *
- * These prove that a Cloudflare Worker (Edge) can sit in front of a
- * TypeScript backend and behave identically to sitting in front of Django.
- */
-
 import { describe, test, expect, beforeEach } from 'bun:test'
 import { ReactContext, client, clearRegistry, handleContextFetch, handleMutationCall, formatInvalidateHeader, generateManifest, MemoryCache, setCache, resetCache, setCacheSecret, deriveCacheKey, cacheGet, cachePut, cachePurge } from '../src'
 
 const UserCtx = new ReactContext('user')
 
 function setupUserContext() {
-    const userProfile = client({ context: UserCtx }, async function userProfile(userId: number) {
+    client({ context: UserCtx }, async function userProfile(userId: number) {
         return { name: `user_${userId}`, email: `user${userId}@test.com` }
     })
 
-    const userOrders = client({ context: UserCtx }, async function userOrders(userId: number) {
+    client({ context: UserCtx }, async function userOrders(userId: number) {
         return { count: userId * 10 }
     })
 
-    const updateProfile = client({ affects: UserCtx }, async function updateProfile(userId: number, name: string) {
+    client({ affects: UserCtx }, async function updateProfile(userId: number, name: string) {
         return { name, email: `user${userId}@test.com` }
     })
 
@@ -122,7 +115,7 @@ describe('Edge Compatibility', () => {
             { context: 'data', params: { name: "O'Brien", tag: 'a;b;c' } },
         ])
 
-        // Parse (what Edge does)
+        // Parse the header the way the Edge worker does
         const segments = header.split(';')
         const ctx = segments[0]
         const params: Record<string, string> = {}
@@ -139,12 +132,6 @@ describe('Edge Compatibility', () => {
     // ── Empty invalidation ─────────────────────────────────────────────
 
     test('no affects = no header, no body key', async () => {
-        client({ context: new ReactContext('plain') }, async function plainFn() {
-            return { ok: true }
-        })
-
-        // A context function called via mutation dispatch (shouldn't have invalidation)
-        // Actually test a function without affects
         clearRegistry()
         client({}, async function noAffects() { return { ok: true } })
         const r = await handleMutationCall('noAffects', {})
@@ -251,6 +238,18 @@ describe('Manifest', () => {
         expect(fn.cache).toBe(60)
     })
 
+    test('cache=false appears in manifest', () => {
+        clearRegistry()
+        const Ctx = new ReactContext('nocache')
+        client({ context: Ctx, cache: false }, async function uncachedFn() {
+            return { value: 1 }
+        })
+
+        const m = generateManifest()
+        const fn = m.contexts.nocache.functions[0]
+        expect(fn.cache).toBe(false)
+    })
+
     test('cache=60 still emits no-store on HTTP', async () => {
         clearRegistry()
         const Ctx = new ReactContext('live')
@@ -294,8 +293,9 @@ describe('Cache Conformance', () => {
     })
 
     test('deriveCacheKey cross-language pin (matches Python)', () => {
-        // These exact values are pinned from Python's derive_cache_key output.
-        // If this test fails, cross-language cache key compatibility is broken.
+        // Literals captured from Python's derive_cache_key under the same
+        // secret. A key derived here is looked up by the Python side, so a
+        // mismatch means the two runtimes address different keyspaces.
         const publicKey = deriveCacheKey(SECRET, 'user', { user_id: '5' }, undefined, 0)
         expect(publicKey).toBe('ctx:user:605a1ca5ad5994e9b765c8d1b330474c2a0d51a7b8fbbdc402f992da7ba902f6')
 
@@ -362,6 +362,27 @@ describe('Cache Conformance', () => {
         setCacheSecret(null)
     })
 
+    test('cache=false context is never stored', async () => {
+        clearRegistry()
+        const Ctx = new ReactContext('volatile')
+        client({ context: Ctx, cache: false }, async function volatileFn(itemId: number) {
+            return { value: itemId }
+        })
+
+        const cache = new MemoryCache()
+        setCache(cache)
+        setCacheSecret(SECRET)
+
+        const r1 = await handleContextFetch('volatile', { itemId: '1' })
+        expect(r1.headers['X-Mizan-Cache']).toBe('MISS')
+
+        const r2 = await handleContextFetch('volatile', { itemId: '1' })
+        expect(r2.headers['X-Mizan-Cache']).toBe('MISS')
+
+        resetCache()
+        setCacheSecret(null)
+    })
+
     test('handleMutationCall purges cache', async () => {
         clearRegistry()
         const Ctx = new ReactContext('product')