Split the client AI module into per-feature files

AGENTS.md

@@ -16,7 +16,7 @@ The local Supabase stack still uses shared default ports and container names. In
 ## System map
 
 - `src/` is the React 18 and TypeScript client. Routes and lazy page entry points live in `src/App.tsx`.
-- `src/lib/stores/` owns browser state and Supabase hydration. `src/lib/ai/client.ts` is the client AI boundary.
+- `src/lib/stores/` owns browser state and Supabase hydration. `src/lib/ai/client.ts` is the client AI boundary: app code imports only from it. The request transport is `request.ts` (streaming Ask uses `streaming.ts`), and each feature has a file in `features/`, mirroring `supabase/functions/ai/features/`.
 - `packages/core/` (`@debatelab/core`, npm workspace) holds platform-neutral shared code: Zod schemas, validation, languages, Crossfire and Sparring logic. No DOM globals, React, or `import.meta` there; old `src/lib/` paths re-export it. Stores and i18n catalogs stay in `src/`.
 - `supabase/functions/` contains Deno Edge Functions. Shared auth, CORS, research, prompts, cost, and validation code lives in `supabase/functions/_shared/`.
 - `supabase/migrations/` is the database history and schema source of truth.

docs/architecture.md

@@ -55,7 +55,7 @@ Client-side environment selection is a developer convenience, not authorization.
 
 ## AI request flow
 
-[`src/lib/ai/client.ts`](../src/lib/ai/client.ts) is the browser AI boundary.
+[`src/lib/ai/client.ts`](../src/lib/ai/client.ts) is the browser AI boundary: app code imports only from it. The request transport is `request.ts` (streaming Ask uses `streaming.ts`), and each feature has a file in `features/`, mirroring `supabase/functions/ai/features/`.
 
 1. A feature page validates input and calls a feature wrapper.
 2. The client reads the current Supabase session.

docs/standards/boundaries.md

@@ -1,6 +1,6 @@
 # Trust boundaries and validation
 
-Part of the [coding standards](../../CODING_STANDARDS.md). The client AI boundary is [`src/lib/ai/client.ts`](../../src/lib/ai/client.ts); the server boundaries are the Edge Function handlers described in [supabase/README.md](../../supabase/README.md).
+Part of the [coding standards](../../CODING_STANDARDS.md). The client AI boundary is [`src/lib/ai/client.ts`](../../src/lib/ai/client.ts), and response validation lives in `src/lib/ai/request.ts`, `src/lib/ai/streaming.ts`, `src/lib/ai/sources.ts`, and each `src/lib/ai/features/*.ts`; the server boundaries are the Edge Function handlers described in [supabase/README.md](../../supabase/README.md).
 
 ## Validate at the boundary, then trust the type
 

e2e/fixtures/ai-responses.ts

@@ -14,7 +14,7 @@ const CORS_HEADERS = {
 };
 
 // The client rejects a generate response whose contention count does not match
-// the requested length (see expectedContentionCount in src/lib/ai/client.ts).
+// the requested length (see expectedContentionCount in src/lib/ai/features/generate.ts).
 const CONTENTION_COUNT: Record<string, number> = { brief: 2, standard: 3, comprehensive: 4 };
 
 const CONTENTIONS = [

eslint.config.js

@@ -4,6 +4,12 @@ import reactHooks from "eslint-plugin-react-hooks";
 import reactRefresh from "eslint-plugin-react-refresh";
 import tseslint from "typescript-eslint";
 
+// The AI core and feature files behind src/lib/ai/client.ts, by alias or
+// relative path, with or without an extension. The server's same-named
+// modules under supabase/functions/ai/ stay importable.
+const aiInternalImport = String.raw`^(?!.*supabase/functions/)(.*/)?ai/(request|errors|sources|text|features(/.*)?)(\.[cm]?[jt]sx?)?/?$`;
+const aiInternalMessage = "Import AI requests and errors from @/lib/ai/client.";
+
 export default tseslint.config(
   { ignores: ["dist", "coverage", ".remember", "packages/**/node_modules", "packages/**/dist"] },
   {
@@ -80,6 +86,26 @@ export default tseslint.config(
       ],
     },
   },
+  {
+    // App code imports AI requests and errors through src/lib/ai/client.ts
+    // only. The core and feature files behind it are internal.
+    files: ["src/**/*.{ts,tsx}", "e2e/**/*.ts", "agentic/**/*.ts"],
+    ignores: ["src/lib/ai/**"],
+    rules: {
+      "no-restricted-imports": [
+        "error",
+        { patterns: [{ regex: aiInternalImport, message: aiInternalMessage }] },
+      ],
+      "no-restricted-syntax": [
+        "error",
+        {
+          // esquery ends a regex at "/", so the pattern spells it as \x2F.
+          selector: `ImportExpression[source.value=/${aiInternalImport.replaceAll("/", "\\x2F")}/]`,
+          message: aiInternalMessage,
+        },
+      ],
+    },
+  },
   {
     // Fixed sleeps pass or fail with machine speed. Wait for a condition.
     files: ["e2e/**/*.ts", "agentic/**/*.ts", ".claude/skills/verify-debatelab/**/*.ts"],