feat: support hierachical modules*.json

Author: guenhter

frontend/omni/.gitignore

@@ -3,3 +3,6 @@ dist/
 src/modules/external-*
 
 public/modules.json
+public/modules*.json
+!public/modules_browser_only.json
+!public/modules_with_backend.json

frontend/omni/CHANGELOG.md

@@ -12,11 +12,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - i18n support via `i18next` with browser language detection (supports English fallback and German). Translations are module-scoped: each module with user-facing strings has its own `locales/de.json`. New `src/modules/i18n/` module provides the `getT(namespace)` helper used by all components.
 - Tools can now be toggled directly from the chat input panel via a wrench-icon popover — no separate Tools page needed.
 - External frontend modules under `src/modules/external-*` can now carry their own npm dependencies through pnpm workspace package discovery, without requiring edits to the root `package.json`.
+- Manifest `includes` support: the root `modules.json` can now declare an `includes` array to compose the module list from multiple JSON files. Included files are merged left-to-right; the root manifest always wins. Per-module `collisionStrategy` (`merge` | `replace` | `drop`) controls collision behaviour, mirroring the backend YAML config loader.
 
 ### Changed
 
 - Switch frontend to Svelte
-- Updated tools fetching and chat tool handling to support `/api/tools` responses as a raw list of function tools (instead of requiring a `{ tools: [...] }` envelope); legacy envelope parsing remains supported for compatibility.
+- Updated tools fetching and chat tool handling to support `/api/tools` responses as a raw list of function tools (instead of requiring a `{ tools: [...] }` envelope)
 - ChatInputPanel redesigned: textarea, model selector, tools selector, and send button are now visually inside a single input box (ai-sdk.dev/examples/chatbot style).
 - Removed the Tools sidebar navigation item and `/tools` route from all module configurations.
 - Made the chat tools selector popover scrollable with a viewport-constrained height so long tool lists remain fully accessible.

frontend/omni/docs/architecture/core.md

@@ -115,6 +115,52 @@ To activate a module, add it to `modules*.json`.
 
 > **Auto-discovery**: The module registry automatically discovers all `.svelte` and `.svelte.ts` files under `src/modules/**` via Vite's `import.meta.glob`. No manual TypeScript registry entry is required.
 
+#### `modules*.json` — top-level structure and includes
+
+A manifest file has the following top-level shape:
+
+```json
+{
+  "version": "1.0.0",
+  "includes": [{ "path": "base.json" }],
+  "modules": [...]
+}
+```
+
+- **version**: manifest format version (currently `"1.0.0"`)
+- **includes** _(optional, root manifest only)_: list of other manifest files to merge in before this file's own modules. Each entry is an object with a `path` field. Relative paths are resolved relative to the current manifest. Nested includes (an included file itself containing `includes`) are not supported and throw an error.
+- **modules**: array of module entries (see below)
+
+**Load order** — mirrors the backend YAML config loader:
+1. Included files are fetched and applied left-to-right; later includes win on collision.
+2. The root manifest's own `modules` are applied last and always win.
+
+**`collisionStrategy`** on a module entry controls what happens when that module's `id` already exists from an earlier include:
+- `"merge"` *(default)* — deep-merges `config`; incoming wins on shared keys. `dependencies` is shallow-merged; incoming wins on key collision.
+- `"replace"` — incoming entry fully replaces the existing one.
+- `"drop"` — removes the existing entry; does not add the incoming one either.
+
+`collisionStrategy` is stripped from the resolved manifest before it is used.
+
+**Example** — composing a deployment-specific manifest from a base:
+
+```json
+{
+  "version": "1.0.0",
+  "includes": [{ "path": "modules_with_backend.json" }],
+  "modules": [
+    {
+      "id": "fetch-service",
+      "path": "@/modules/fetch-service/sessionFetchService/create",
+      "collisionStrategy": "replace",
+      "dependencies": {
+        "module:sessionService": "session-service"
+      }
+    }
+  ]
+}
+```
+
 #### `modules*.json` — regular module entry
 
 ```json

frontend/omni/src/core/module-system/ModulesProvider.svelte

@@ -4,7 +4,7 @@ import { setContext, untrack } from "svelte";
 import { ComponentResolver } from "./componentResolver";
 import { MODULES_KEY, type Modules } from "./index";
 import { resolveManifestDependencies } from "./manifestDependencyResolver";
-import { fetchManifestJson } from "./manifestJson";
+import { resolveManifest } from "./manifestJson";
 import { ActiveModulesImpl } from "./module";
 
 interface Props {
@@ -28,7 +28,7 @@ const modules: Modules = {
 setContext(MODULES_KEY, modules);
 
 // untrack: manifest path is intentionally captured once at mount time
-const ready = fetchManifestJson(untrack(() => manifestPath)).then(
+const ready = resolveManifest(untrack(() => manifestPath)).then(
     async (json) => {
         const activeEntries = resolveManifestDependencies(json.modules, []);
         const componentResolver =