fix(sidebar-tabs): use text-selection highlight as copy indicator instead of swapping text

2 files changed, 18 insertions, 33 deletions

diff --git a/src/features/tabs/ui.test.ts b/src/features/tabs/ui.test.ts
index 57f9bc1..9af4cd1 100644
--- a/src/features/tabs/ui.test.ts
+++ b/src/features/tabs/ui.test.ts
@@ -230,7 +230,7 @@ describe("TabList", () => {
     expect(onRename).toHaveBeenCalledWith("c1", "Renamed");
   });
 
-  it("copies the full conversation id to the clipboard and shows 'Copied!' when the ID badge is clicked", async () => {
+  it("copies the conversation id to the clipboard and highlights the badge text when clicked", async () => {
     const writeText = vi.fn().mockResolvedValue(undefined);
     Object.defineProperty(navigator, "clipboard", {
       value: { writeText },
@@ -254,8 +254,13 @@ describe("TabList", () => {
 
     expect(writeText).toHaveBeenCalledTimes(1);
     expect(writeText).toHaveBeenCalledWith("c1");
-    // The badge briefly shows a "Copied!" confirmation.
-    expect(idBadge).toHaveTextContent("Copied!");
+    // The badge text is NOT swapped (no width shift) — the highlight (selection)
+    // is the only indicator.
+    expect(idBadge).toHaveTextContent("c1");
+    expect(idBadge).not.toHaveTextContent("Copied");
+    // The badge text is selected (highlighted) as the copy indicator.
+    const selection = window.getSelection();
+    expect(selection?.toString()).toBe("c1");
     // Clicking the ID must NOT switch tabs (the badge stops propagation).
     expect(onSelect).not.toHaveBeenCalled();
   });
diff --git a/src/features/tabs/ui/TabList.svelte b/src/features/tabs/ui/TabList.svelte
index 40f95cd..031743c 100644
--- a/src/features/tabs/ui/TabList.svelte
+++ b/src/features/tabs/ui/TabList.svelte
@@ -58,36 +58,21 @@
 
 	// Click-to-copy the agent (conversation) id: clicking the ID badge copies the
 	// FULL conversationId to the clipboard (the stable, useful id — the badge
-	// only shows a short prefix) and briefly highlights the badge as feedback.
-	// Clipboard is the edge effect; absent (insecure context) → select the badge
-	// text so the user can Ctrl+C manually.
-	let copiedId = $state<string | null>(null);
-	let copyTimer: ReturnType<typeof setTimeout> | undefined;
-
+	// only shows a short prefix) and highlights the badge text as feedback. The
+	// highlight (text selection) is the indicator — no text is swapped, so the
+	// badge keeps a stable width. If the clipboard write fails, the selection is
+	// already in place so the user can Ctrl+C the text manually.
 	async function copyId(conversationId: string, el: HTMLElement): Promise<void> {
+		selectText(el);
 		const clipboard = navigator.clipboard;
-		if (clipboard === undefined) {
-			selectText(el);
-			flashCopied(conversationId);
-			return;
-		}
+		if (clipboard === undefined) return;
 		try {
 			await clipboard.writeText(conversationId);
-			flashCopied(conversationId);
 		} catch {
-			selectText(el);
-			flashCopied(conversationId);
+			// Selection already lets the user copy manually.
 		}
 	}
 
-	function flashCopied(conversationId: string): void {
-		copiedId = conversationId;
-		clearTimeout(copyTimer);
-		copyTimer = setTimeout(() => {
-			copiedId = null;
-		}, 1200);
-	}
-
 	function selectText(el: HTMLElement): void {
 		const range = document.createRange();
 		range.selectNodeContents(el);
@@ -117,21 +102,16 @@
 			>
 				<button
 					type="button"
-					class="shrink-0 rounded px-1 py-0.5 font-mono text-[10px] leading-none transition-colors {copiedId ===
-					tab.conversationId
-						? "bg-success text-success-content"
-						: "bg-base-300 text-base-content/60 hover:bg-primary hover:text-primary-content"}"
+					class="shrink-0 rounded bg-base-300 px-1 py-0.5 font-mono text-[10px] leading-none text-base-content/60 transition-colors hover:bg-primary hover:text-primary-content"
 					data-copy-id={tab.conversationId}
-					title={copiedId === tab.conversationId ? "Copied!" : "Click to copy conversation id"}
+					title="Click to copy conversation id"
 					aria-label={`Copy conversation id ${tab.conversationId}`}
 					onclick={(e) => {
 						e.stopPropagation();
 						void copyId(tab.conversationId, e.currentTarget);
 					}}
 				>
-					{copiedId === tab.conversationId
-						? "Copied!"
-						: (handles.get(tab.conversationId) ?? tab.conversationId)}
+					{handles.get(tab.conversationId) ?? tab.conversationId}
 				</button>
 				{#if editingId === tab.conversationId}
 					<input