diff --git a/.gitignore b/.gitignore
index 858543d..70017bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 webclient/
 node_modules/
 dist/
+.tmp
diff --git a/docs/vue.md b/docs/vue.md
index 0a3e838..c0a081b 100644
--- a/docs/vue.md
+++ b/docs/vue.md
@@ -87,6 +87,8 @@
 toast.success({ title: "Saved", text: "Changes applied" });
 ```
 
+`GnToastProvider` intentionally keeps a single visible toast. Showing a new toast replaces the previous one. Use this contract for compact app feedback; add queue support in this repository if a project needs stacked notifications.
+
 ## Build
 
 ```bash
diff --git a/docs/vue/ai-usage-guide.md b/docs/vue/ai-usage-guide.md
index dbc682f..3dfd160 100644
--- a/docs/vue/ai-usage-guide.md
+++ b/docs/vue/ai-usage-guide.md
@@ -117,3 +117,10 @@
 Warnings about `/assets/fonts/...` in Vite builds are expected with the current CSS contract. They mean the host app must serve GNexus UI Kit assets at `/assets`.
 
 The local example clears `examples/vue/node_modules/.vite` before build because `gnexus-ui-kit` is linked from the repository root and Vite can otherwise reuse stale optimized metadata after `dist/vue` changes.
+
+## Behavior Contracts
+
+- `GnModal` and `GnDrawer` handle Escape, focus return, and Tab focus trapping.
+- `GnToastProvider` is single-toast by design: a new toast replaces the current one.
+- `GnCombobox` owns combobox/listbox ARIA and keyboard movement.
+- `GnFileUpload` owns preview object URLs and cleans them up on remove/unmount.
diff --git a/docs/vue/migration-policy.md b/docs/vue/migration-policy.md
index 30daf48..ccf0108 100644
--- a/docs/vue/migration-policy.md
+++ b/docs/vue/migration-policy.md
@@ -32,6 +32,8 @@
 - improving keyboard/focus behavior without changing public API;
 - adding docs and examples.
 
+Document behavior changes when they affect user expectations, even if they are not breaking. Examples: focus trapping, toast queueing policy, or file preview cleanup.
+
 ## Downstream Rules
 
 Vue projects should not:
diff --git a/src/vue/components/GnCombobox.js b/src/vue/components/GnCombobox.js
index 7c21ef0..42db564 100644
--- a/src/vue/components/GnCombobox.js
+++ b/src/vue/components/GnCombobox.js
@@ -1,6 +1,8 @@
 import { computed, defineComponent, h, nextTick, ref } from "vue";
 import { cx, eventValue, iconNode } from "../utils.js";
 
+let comboboxId = 0;
+
 export default defineComponent({
 	name: "GnCombobox",
 	inheritAttrs: false,
@@ -16,6 +18,8 @@
 	},
 	emits: ["update:modelValue", "select"],
 	setup(props, { attrs, emit }) {
+		const id = `gn-combobox-${++comboboxId}`;
+		const listboxId = `${id}-listbox`;
 		const open = ref(false);
 		const focused = ref(-1);
 		const inputRef = ref(null);
@@ -70,10 +74,16 @@
 				h("input", {
 					...attrs,
 					ref: inputRef,
+					id,
 					type: "text",
 					value: props.modelValue,
 					placeholder: props.placeholder,
 					autocomplete: "off",
+					role: "combobox",
+					"aria-autocomplete": "list",
+					"aria-expanded": open.value ? "true" : "false",
+					"aria-controls": listboxId,
+					"aria-activedescendant": focused.value >= 0 ? `${id}-option-${focused.value}` : undefined,
 					class: cx("input", attrs.class),
 					onFocus: () => {
 						open.value = true;
@@ -95,8 +105,15 @@
 				h("div", { class: cx("advanced-select", { "a-show": open.value }) }, [
 					h("div", { class: "popup-options-container" }, [
 						h("div", { class: cx("not-found", { show: !filtered.value.length }) }, props.notFoundText),
-						h("div", { class: cx("options", { show: filtered.value.length }) }, filtered.value.map((option, index) => h("div", {
+						h("div", {
+							id: listboxId,
+							class: cx("options", { show: filtered.value.length }),
+							role: "listbox"
+						}, filtered.value.map((option, index) => h("div", {
+							id: `${id}-option-${index}`,
 							class: cx("option", { focus: index === focused.value }),
+							role: "option",
+							"aria-selected": index === focused.value ? "true" : "false",
 							"data-value": option.value,
 							"data-display-value": option.label,
 							onMousedown: event => {
diff --git a/src/vue/components/GnDrawer.js b/src/vue/components/GnDrawer.js
index 6e8f05d..b9c40a8 100644
--- a/src/vue/components/GnDrawer.js
+++ b/src/vue/components/GnDrawer.js
@@ -1,5 +1,5 @@
 import { defineComponent, h, nextTick, onBeforeUnmount, ref, Teleport, watch } from "vue";
-import { cx, iconNode } from "../utils.js";
+import { cx, iconNode, trapFocus } from "../utils.js";
 
 let drawerId = 0;
 
@@ -23,6 +23,8 @@
 			if(event.key === "Escape") {
 				event.preventDefault();
 				close();
+			} else {
+				trapFocus(event, panelRef.value);
 			}
 		};
 
diff --git a/src/vue/components/GnFileUpload.js b/src/vue/components/GnFileUpload.js
index 359eb39..afaff84 100644
--- a/src/vue/components/GnFileUpload.js
+++ b/src/vue/components/GnFileUpload.js
@@ -1,4 +1,4 @@
-import { defineComponent, h, ref } from "vue";
+import { defineComponent, h, onBeforeUnmount, ref, watch } from "vue";
 import { iconNode } from "../utils.js";
 import GnButton from "./GnButton.js";
 import GnBadge from "./GnBadge.js";
@@ -34,12 +34,25 @@
 	emits: ["update:modelValue", "change"],
 	setup(props, { emit, slots }) {
 		const urls = ref(new Map());
+		const revokeFile = file => {
+			const url = urls.value.get(file);
+
+			if(url) {
+				URL.revokeObjectURL(url);
+				urls.value.delete(file);
+			}
+		};
+		const revokeAll = () => {
+			urls.value.forEach(url => URL.revokeObjectURL(url));
+			urls.value.clear();
+		};
 		const setFiles = fileList => {
 			const files = Array.from(fileList || []);
 			emit("update:modelValue", files);
 			emit("change", files);
 		};
 		const remove = index => {
+			revokeFile(props.modelValue[index]);
 			const files = props.modelValue.filter((_, itemIndex) => itemIndex !== index);
 			emit("update:modelValue", files);
 			emit("change", files);
@@ -56,6 +69,17 @@
 			return urls.value.get(file);
 		};
 
+		watch(() => props.modelValue, files => {
+			const active = new Set(files);
+			[...urls.value.keys()].forEach(file => {
+				if(!active.has(file)) {
+					revokeFile(file);
+				}
+			});
+		});
+
+		onBeforeUnmount(revokeAll);
+
 		return () => h("div", { class: "file-upload-panel" }, [
 			h("div", { class: "file-upload-form" }, [
 				h("div", { class: "file-upload-header" }, [
@@ -101,7 +125,10 @@
 					h(GnButton, {
 						variant: "secondary",
 						size: "sm",
-						onClick: () => setFiles([])
+						onClick: () => {
+							revokeAll();
+							setFiles([]);
+						}
 					}, () => "Reset")
 				])
 			])
diff --git a/src/vue/components/GnModal.js b/src/vue/components/GnModal.js
index 304f23d..a5f10dc 100644
--- a/src/vue/components/GnModal.js
+++ b/src/vue/components/GnModal.js
@@ -1,5 +1,5 @@
 import { defineComponent, h, nextTick, onBeforeUnmount, ref, Teleport, watch } from "vue";
-import { iconNode } from "../utils.js";
+import { iconNode, trapFocus } from "../utils.js";
 
 let modalId = 0;
 
@@ -23,6 +23,8 @@
 			if(event.key === "Escape") {
 				event.preventDefault();
 				close();
+			} else {
+				trapFocus(event, dialogRef.value);
 			}
 		};
 		const focusDialog = () => {
diff --git a/src/vue/utils.js b/src/vue/utils.js
index 1c1941f..d7565fb 100644
--- a/src/vue/utils.js
+++ b/src/vue/utils.js
@@ -66,3 +66,38 @@
 
 	return target.value;
 }
+
+export const focusableSelector = [
+	"a[href]",
+	"button:not([disabled])",
+	"input:not([disabled])",
+	"select:not([disabled])",
+	"textarea:not([disabled])",
+	"[tabindex]:not([tabindex='-1'])"
+].join(",");
+
+export function trapFocus(event, root) {
+	if(event.key !== "Tab" || !root) {
+		return;
+	}
+
+	const focusable = [...root.querySelectorAll(focusableSelector)]
+		.filter(node => !node.hasAttribute("disabled") && node.offsetParent !== null);
+
+	if(!focusable.length) {
+		event.preventDefault();
+		root.focus();
+		return;
+	}
+
+	const first = focusable[0];
+	const last = focusable[focusable.length - 1];
+
+	if(event.shiftKey && document.activeElement === first) {
+		event.preventDefault();
+		last.focus();
+	} else if(!event.shiftKey && document.activeElement === last) {
+		event.preventDefault();
+		first.focus();
+	}
+}