Keep welcome screen free of docked canvas

Route non-action canvas surfaces to their floating/modal forms while the welcome screen is active, and keep the canvas rail/shell hidden until a chat is selected.

Open the welcome Files quick action through the File Browser modal directly so the first screen remains composed.

Document the welcome/canvas boundary in the local DOX contracts and add focused regression assertions for the canvas guard and Files quick action.

tests/test_browser_agent_regressions.py

@@ -830,7 +830,7 @@ def test_surface_buttons_keep_modal_and_canvas_entry_points_separate():
         canvas_store.index("async undockActiveSurface")
     ]
     should_render_block = canvas_store[
-        canvas_store.index("shouldRender()"):
+        canvas_store.index("\n  shouldRender()"):
         canvas_store.index("};\n\nexport const store")
     ]
     surface_button_block = surfaces_js[
@@ -845,6 +845,7 @@ def test_surface_buttons_keep_modal_and_canvas_entry_points_separate():
     assert "markSurfaceMounted(targetId)" in canvas_store
     assert "isSurfaceRendered(id)" in canvas_store
     assert "isSurfaceVisible(id)" in canvas_store
+    assert 'import { store as chatsStore } from "/components/sidebar/chats/chats-store.js";' in canvas_store
     assert "async openLatest(surfaceId" in canvas_store
     assert "async openModalSurface(surfaceId" in canvas_store
     assert "this.recordSurfaceMode(targetId, SURFACE_MODE_DOCKED" in canvas_store
@@ -856,8 +857,10 @@ def test_surface_buttons_keep_modal_and_canvas_entry_points_separate():
     assert "return await this.openModalSurface(targetId, payload);" in canvas_store
     assert "return await this.open(targetId, payload);" in canvas_store
     assert 'return await this.open(this.activeSurfaceId || this.panelSurfaces[0]?.id || "", { source: "mobile-toggle" });' in canvas_store
-    assert "return true;" in should_render_block
+    assert "isWelcomeVisible()" in canvas_store
+    assert "return !this.isWelcomeVisible();" in should_render_block
     assert "isMobileMode" not in should_render_block
+    assert 'document.body.classList.toggle("right-canvas-open", this.isOpen && !this.isMobileMode && this.shouldRender());' in canvas_store
     assert "this.mountedSurfaces = {}" not in close_block
     assert "surface?.close" not in close_block
     assert "this.mountedSurfaces = {}" not in undock_block

tests/test_file_browser_navigation.py

@@ -144,6 +144,7 @@ def test_file_browser_is_registered_as_right_canvas_surface() -> None:
     register = read("extensions", "webui", "right_canvas_register_surfaces", "register-files.js")
     panel = read("extensions", "webui", "right-canvas-panels", "files-panel.html")
     input_store = read("webui", "components", "chat", "input", "input-store.js")
+    welcome_store = read("webui", "components", "welcome", "welcome-store.js")
 
     assert 'id: "files"' in surfaces
     assert 'title: "Files"' in surfaces
@@ -167,6 +168,9 @@ def test_file_browser_is_registered_as_right_canvas_surface() -> None:
     assert 'data-surface-id="files"' in panel
     assert 'path="modals/file-browser/file-browser.html" mode="canvas"' in panel
     assert 'openLatestSurface("files"' in input_store
+    assert 'import { store as fileBrowserStore } from "/components/modals/file-browser/file-browser-store.js";' in welcome_store
+    assert "fileBrowserStore.open()" in welcome_store
+    assert "chatInputStore.browseFiles" not in welcome_store
 
 
 def test_file_browser_reports_missing_directory(tmp_path: Path) -> None:

webui/components/canvas/AGENTS.md

@@ -15,6 +15,7 @@
 - Keep registered surfaces compatible with WebUI extension hooks.
 - Preserve responsive layout and avoid overlapping the chat/sidebar shells.
 - Right-canvas rail and tab buttons are explicit canvas entry points above the mobile breakpoint; at mobile widths, keep the rail visible but route non-action surfaces into floating modals instead of the side canvas shell.
+- Keep the right-canvas rail and docked shell hidden while the welcome screen is active; non-action surface opens during welcome must route into floating/modal surfaces instead of docking beside the welcome screen.
 - In mobile mode, keep the rail below blocking modal layers and compact it on very narrow screens instead of letting it cover modal content.
 
 ## Work Guidance

webui/components/canvas/right-canvas-store.js

@@ -1,4 +1,5 @@
 import { createStore } from "/js/AlpineStore.js";
+import { store as chatsStore } from "/components/sidebar/chats/chats-store.js";
 import { callJsExtensions } from "/js/extensions.js";
 import {
   SURFACE_MODE_DOCKED,
@@ -135,6 +136,10 @@ const model = {
       return true;
     }
 
+    if (!this.shouldRender()) {
+      return await this.openModalSurface(targetId, payload);
+    }
+
     if (this.isMobileMode) {
       this.activeSurfaceId = targetId;
       this.isOpen = false;
@@ -342,6 +347,7 @@ const model = {
   },
 
   async toggleCanvas() {
+    if (!this.shouldRender()) return false;
     if (this.isMobileMode) {
       return await this.open(this.activeSurfaceId || this.panelSurfaces[0]?.id || "", { source: "mobile-toggle" });
     }
@@ -476,7 +482,7 @@ const model = {
   applyLayoutState() {
     this.updateLayoutMode();
     document.documentElement.style.setProperty("--right-canvas-width", `${this.width}px`);
-    document.body.classList.toggle("right-canvas-open", this.isOpen && !this.isMobileMode);
+    document.body.classList.toggle("right-canvas-open", this.isOpen && !this.isMobileMode && this.shouldRender());
     document.body.classList.toggle("right-canvas-overlay-mode", this.isOverlayMode);
     document.body.classList.toggle("right-canvas-mobile-mode", this.isMobileMode);
   },
@@ -517,8 +523,12 @@ const model = {
     return this.currentSurface()?.title || "Canvas";
   },
 
+  isWelcomeVisible() {
+    return !chatsStore.selected;
+  },
+
   shouldRender() {
-    return true;
+    return !this.isWelcomeVisible();
   },
 };
 

webui/components/welcome/AGENTS.md

@@ -16,6 +16,7 @@
 - Do not show setup prompts for already configured plugins when backend status can prevent it.
 - The welcome screen mounts the shared chat composer to start a new chat; keep it mutually exclusive with the normal chat input DOM.
 - Render `system-resources` as the dedicated System Resources panel, not as a generic alert banner.
+- Utility quick actions from welcome must keep the first screen intact; use modal/floating entry points instead of docking the right canvas beside welcome content.
 
 ## Work Guidance
 

webui/components/welcome/welcome-store.js

@@ -2,7 +2,7 @@ import { createStore } from "/js/AlpineStore.js";
 import { store as chatsStore } from "/components/sidebar/chats/chats-store.js";
 import { store as memoryStore } from "/plugins/_memory/webui/memory-dashboard-store.js";
 import { store as projectsStore } from "/components/projects/projects-store.js";
-import { store as chatInputStore } from "/components/chat/input/input-store.js";
+import { store as fileBrowserStore } from "/components/modals/file-browser/file-browser-store.js";
 import * as API from "/js/api.js";
 import { getCurrentUserISOString } from "/js/time-utils.js";
 
@@ -261,7 +261,7 @@ const model = {
         memoryStore.openModal();
         break;
       case "files":
-        chatInputStore.browseFiles();
+        fileBrowserStore.open();
         break;
       case "website":
         window.open("https://agent-zero.ai", "_blank");