ui: Restructure repo to use tools/ui folder and ui / UI / llama-ui / LLAMA_UI naming (#23064)

* webui: Move static build output from `tools/server/public` to `build/ui` directory

* refactor: Move to `tools/ui`

* refactor: rename CMake variables and preprocessor defines

- Rename LLAMA_BUILD_WEBUI -> LLAMA_BUILD_UI (old kept as deprecated)
- Rename LLAMA_USE_PREBUILT_WEBUI -> LLAMA_USE_PREBUILT_UI (old kept as deprecated)
- Backward compat: old vars auto-forward to new ones with DEPRECATION warning
- Rename internal vars: WEBUI_SOURCE -> UI_SOURCE, WEBUI_SOURCE_DIR -> UI_SOURCE_DIR, etc.
- Rename HF bucket: LLAMA_WEBUI_HF_BUCKET -> LLAMA_UI_HF_BUCKET
- Emit both LLAMA_BUILD_WEBUI and LLAMA_BUILD_UI preprocessor defines
- Emit both LLAMA_WEBUI_DEFAULT_ENABLED and LLAMA_UI_DEFAULT_ENABLED

* refactor: rename CLI flags (--webui -> --ui) with backward compat

- Add --ui/--no-ui (old --webui/--no-webui kept as deprecated aliases)
- Add --ui-config (old --webui-config kept as deprecated alias)
- Add --ui-config-file (old --webui-config-file kept as deprecated alias)
- Add --ui-mcp-proxy/--no-ui-mcp-proxy (old --webui-mcp-proxy kept as deprecated)
- Add new env vars: LLAMA_ARG_UI, LLAMA_ARG_UI_CONFIG, LLAMA_ARG_UI_CONFIG_FILE, LLAMA_ARG_UI_MCP_PROXY
- C++ struct fields: params.ui, params.ui_config_json, params.ui_mcp_proxy added alongside old fields
- Backward compat: old fields synced to new ones in g_params_to_internals

* refactor: update C++ server internals with backward compat

- Rename json_webui_settings -> json_ui_settings (both kept in server_context_meta)
- Rename params.webui usage -> params.ui (both synced, old still works)
- JSON API emits both "ui"/"ui_settings" and "webui"/"webui_settings" keys
- Server routes use params.ui_mcp_proxy || params.webui_mcp_proxy
- Preprocessor guards use #if defined(LLAMA_BUILD_UI) || defined(LLAMA_BUILD_WEBUI)

* refactor: rename CI/CD workflows, artifacts, and build script

- Rename webui-build.yml -> ui-build.yml; artifact webui-build -> ui-build
- Rename webui-publish.yml -> ui-publish.yml; var HF_BUCKET_WEBUI_STATIC_OUTPUT -> HF_BUCKET_UI_STATIC_OUTPUT
- Rename server-webui.yml -> server-ui.yml; job webui-build/checks -> ui-build/checks
- Update server.yml: job/artifact refs webui-build -> ui-build
- Update release.yml: all webui-build/publish refs -> ui-build/publish; HF_TOKEN_WEBUI_STATIC_OUTPUT -> HF_TOKEN_UI_STATIC_OUTPUT
- Update server-self-hosted.yml: webui-build -> ui-build
- Update build-self-hosted.yml: HF_WEBUI_VERSION -> HF_UI_VERSION
- Rename webui-download.cmake -> ui-download.cmake (internal refs updated)
- Update labeler.yml: server/webui -> server/ui path label

* docs: update CODEOWNERS and server README docs

- Update CODEOWNERS: team ggml-org/llama-webui -> ggml-org/llama-ui, path /tools/server/webui/ -> /tools/ui/
- Update server README.md: CLI tables show --ui flags with deprecated --webui aliases
- Update server README-dev.md: "WebUI" -> "UI", paths updated to tools/ui/

* fix: Small fixes for UI build

* fix: CMake.txt syntax

* chore: Formatting

* fix: `.editorconfig` for llama-ui

* chore: Formatting

* refactor: Use `APP_NAME` in Error route

* refactor: Cleanup

* refactor: Single migration service

* make llama-ui a linkable target

* fix: UI Build output

* fix: Missing change

* fix: separate llama-ui npm build output into build/tools/ui/dist subfolder + use cmake npm build instead of downloading ui-build.yml artifacts in CI

* refactor: UI workflows cleanup

---------

Co-authored-by: Xuan Son Nguyen <son@huggingface.co>

tools/server/server-context.cpp

@@ -671,7 +671,8 @@ private:
 
     server_metrics metrics;
 
-    json json_webui_settings = json::object();
+    json json_ui_settings = json::object();    // Primary: new name
+    json json_webui_settings = json::object();    // Deprecated: use json_ui_settings instead (kept for compat)
 
     // Necessary similarity of prompt for slot selection
     float slot_prompt_similarity = 0.0f;
@@ -996,13 +997,18 @@ private:
             }
         }
 
-        // populate webui settings
+        // populate UI settings (from either new ui_config_json or deprecated webui_config_json)
         {
-            if (!params_base.webui_config_json.empty()) {
+            const std::string & cfg = !params_base.ui_config_json.empty()
+                ? params_base.ui_config_json
+                : params_base.webui_config_json;
+            if (!cfg.empty()) {
                 try {
-                    json_webui_settings = json::parse(params_base.webui_config_json);
+                    json json_settings = json::parse(cfg);
+                    json_ui_settings = json_settings;
+                    json_webui_settings = json_settings; // deprecated: keep in sync
                 } catch (const std::exception & e) {
-                    SRV_ERR("%s: failed to parse webui config: %s\n", __func__, e.what());
+                    SRV_ERR("%s: failed to parse UI config: %s\n", __func__, e.what());
                     return false;
                 }
             }
@@ -3292,7 +3298,8 @@ server_context_meta server_context::get_meta() const {
         /* has_mtmd               */ impl->mctx != nullptr,
         /* has_inp_image          */ impl->chat_params.allow_image,
         /* has_inp_audio          */ impl->chat_params.allow_audio,
-        /* json_webui_settings    */ impl->json_webui_settings,
+        /* json_ui_settings       */ impl->json_ui_settings,
+        /* json_webui_settings    */ impl->json_webui_settings,  // Deprecated
         /* slot_n_ctx             */ impl->get_slot_n_ctx(),
         /* pooling_type           */ llama_pooling_type(impl->ctx_tgt),
 
@@ -3814,8 +3821,12 @@ void server_routes::init_routes() {
             { "endpoint_slots",              params.endpoint_slots },
             { "endpoint_props",              params.endpoint_props },
             { "endpoint_metrics",            params.endpoint_metrics },
-            { "webui",                       params.webui },
-            { "webui_settings",              meta->json_webui_settings },
+            // New keys
+            { "ui",                           params.ui },
+            { "ui_settings",                  meta->json_ui_settings },
+            // Deprecated: use ui/ui_settings instead (kept for backward compat)
+            { "webui",                        params.webui },
+            { "webui_settings",               meta->json_webui_settings },
             { "chat_template",               tmpl_default },
             { "chat_template_caps",          meta->chat_template_caps },
             { "bos_token",                   meta->bos_token_str },