fix(sessions): apply a run proposal once, not on every remount

The detail page remounts under its viewer whenever the item is deployed,
refreshed or pinned to a version, and came back with its own latch reset — so
the agent's proposal was pushed in again, over whatever the reader had typed
since, bringing back a note they had dismissed. The proposal was made once.

The viewer now holds it as pending until the page reports applying it, and says
separately whether to credit the agent: the note stands until dismissed, the
values land once.

Also from the CI round's nits:
- a pinned viewer the handover re-points is brought to the front, since the
  call is about to say the page is open
- offerMessage's doc described inputs it no longer carries; applyInputs owns
  them, deliberately unconditional on the message landing

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/details/FlowDetail.svelte

@@ -104,6 +104,8 @@
 		active = true,
 		embedded = false,
 		seededRun,
+		seededByAgent = false,
+		onSeedApplied,
 		onClearSeededRun,
 		onLoadState
 	}: {
@@ -125,7 +127,12 @@
 		 * note above them. `seq` identifies the request, so a second one re-seeds a page that
 		 * is already open. */
 		seededRun?: { args: Record<string, any>; seq: number }
-		/** The reader dismissed that note. The values stay in the fields. */
+		/** Whether to say the agent filled them. Outlives `seededRun`, since the note stands
+		 * until the reader dismisses it. */
+		seededByAgent?: boolean
+		/** Applied, so the host stops offering them. */
+		onSeedApplied?: () => void
+		/** The reader dismissed the note. The values stay in the fields. */
 		onClearSeededRun?: () => void
 		/** How the load ended, for a host that renders its own state around this page. */
 		onLoadState?: (state: 'loaded' | 'not_found') => void
@@ -402,9 +409,11 @@
 			// would put words in the box long after they were proposed. The card still shows
 			// what was asked for.
 			if (typeof message === 'string' && message) flowChat.offerMessage(message)
+			onSeedApplied?.()
 		} else if (runForm) {
 			seededSeq = seededRun.seq
 			runForm.setArgs(seededRun.args)
+			onSeedApplied?.()
 		}
 	})
 
@@ -920,7 +929,7 @@
 									/>
 								{/if}
 
-								{#if seededRun}
+								{#if seededByAgent}
 									<InputSelectedBadge inputSelected="agent" onReject={() => onClearSeededRun?.()} />
 								{/if}
 

frontend/src/lib/components/details/ScriptDetail.svelte

@@ -127,6 +127,8 @@
 		active = true,
 		embedded = false,
 		seededRun,
+		seededByAgent = false,
+		onSeedApplied,
 		onClearSeededRun,
 		onLoadState
 	}: {
@@ -143,12 +145,19 @@
 		/** Rendered inside a page that is not the script's own (an AI session preview tab), whose
 		 * URL this must leave alone and which a cross-workspace link must not navigate away. */
 		embedded?: boolean
-		/** Arguments a chat tool filled this form with when it opened the page. Nothing waits
-		 * on them: the page runs as it always does, and these only seed the fields and put a
-		 * note above them. `seq` identifies the request, so a second one re-seeds a page that
-		 * is already open. */
+		/** Arguments a chat tool proposed when it opened the page, for as long as they have
+		 * still to be applied. Nothing waits on them: the page runs as it always does, and
+		 * these only fill the fields. `seq` identifies the request, so a second one re-seeds a
+		 * page already open. Gone once applied — this page remounts under its host on a
+		 * deploy, a refresh or a version pin, and applying again would overwrite what the
+		 * reader has typed since. */
 		seededRun?: { args: Record<string, any>; seq: number }
-		/** The reader dismissed that note. The values stay in the fields. */
+		/** Whether to say the agent filled them. Outlives `seededRun`, since the note stands
+		 * until the reader dismisses it. */
+		seededByAgent?: boolean
+		/** Applied, so the host stops offering them. */
+		onSeedApplied?: () => void
+		/** The reader dismissed the note. The values stay in the fields. */
 		onClearSeededRun?: () => void
 		/** How the load ended, for a host that renders its own state around this page.
 		 * Providing it also suppresses the "could not load" toast: a 404 here is the normal
@@ -432,6 +441,7 @@
 		if (seededSeq === seededRun.seq) return
 		seededSeq = seededRun.seq
 		runForm.setArgs(seededRun.args)
+		onSeedApplied?.()
 	})
 
 	// Read once on purpose: these args seed the form, so tracking the fragment would
@@ -1105,7 +1115,7 @@
 								/>
 							{/if}
 
-							{#if seededRun}
+							{#if seededByAgent}
 								<InputSelectedBadge inputSelected="agent" onReject={() => onClearSeededRun?.()} />
 							{/if}
 							<RunForm

frontend/src/lib/components/flows/conversations/FlowChat.svelte

@@ -178,14 +178,10 @@
 	const shownKey = $derived(poolState?.shownKey)
 
 	/** Put a message in the composer of the conversation on screen, for the reader to edit and
-	 * send, and set the flow's other inputs to go with it. Returns false when that composer
-	 * already holds a draft — it is never overwritten, and the caller leaves the message where
-	 * the reader can still see it.
-	 *
-	 * `inputs` are the run's non-message arguments: a chat flow's schema can declare more than
-	 * `user_message`, and a message sent without them would run on saved values or schema
-	 * defaults — a different run from the one being offered. Applied only alongside a message
-	 * the composer took, so a declined offer leaves the reader's settings alone. */
+	 * send. Returns false when that composer already holds a draft — it is never overwritten,
+	 * and the caller drops the message rather than holding it. The run's other arguments go
+	 * through {@link applyInputs}, which is deliberately not conditional on this: they belong
+	 * to the proposal whether or not its message could land. */
 	export function offerMessage(text: string): boolean {
 		const panel = shownKey ? pool?.get(shownKey) : undefined
 		return panel?.host.offerMessage(text) ?? false

frontend/src/lib/components/sessions/ItemViewerView.svelte

@@ -69,22 +69,40 @@
 	// Arguments a chat tool filled this item's run form with when it opened the page. Nothing
 	// is waiting on them: the reader runs the page as they would with no chat open, and the
 	// note above the form only says where the values came from.
-	// Taken from the runtime once and held here: the request belongs to the turn that made it,
-	// so leaving it in the map would re-apply a stale proposal — and reannounce it — to every
-	// later open of this item's deployed page.
-	// Carries the item it was filed under: this tab re-points to another item in place rather
-	// than remounting, so a seed held without its key would be pushed into the next item's
-	// form — replacing its own defaults — under a note crediting the agent for them.
+	//
+	// Taken from the runtime once and held here, because the request belongs to the turn that
+	// made it: left in the map it would re-seed every later open of this item's page. The item
+	// it was filed under rides along, since this tab re-points to another item in place rather
+	// than remounting — a seed held without its key would land in the next item's form,
+	// replacing its own defaults, under a note crediting the agent for them.
+	//
+	// `pending` is what the page has still to apply, and the detail page clears it by reporting
+	// that it has. The two are separate because the detail page remounts under this one (a
+	// deploy, a refresh, a version pin) and comes back with its own latch reset: without that,
+	// each remount would push the proposal in again, over whatever the reader has since typed,
+	// and bring back a note they had dismissed. The agent proposed once.
 	let held = $state<
-		{ kind: SessionTargetKind; path: string; args: Record<string, any>; seq: number } | undefined
+		| {
+				kind: SessionTargetKind
+				path: string
+				args: Record<string, any>
+				seq: number
+				pending: boolean
+		  }
+		| undefined
 	>(undefined)
-	const seededRun = $derived(held?.kind === kind && held.path === path ? held : undefined)
+	const forThisItem = $derived(held?.kind === kind && held.path === path ? held : undefined)
+	const seededRun = $derived(
+		forThisItem?.pending ? { args: forThisItem.args, seq: forThisItem.seq } : undefined
+	)
+	/** The note stands until the reader dismisses it, which outlives the one application. */
+	const seededByAgent = $derived(!!forThisItem)
 	$effect(() => {
-		const pending = runtime.seededRunArgsFor(kind, path)
-		if (!pending) return
+		const incoming = runtime.seededRunArgsFor(kind, path)
+		if (!incoming) return
 		const [k, p] = [kind, path]
 		untrack(() => {
-			held = { kind: k, path: p, ...pending }
+			held = { kind: k, path: p, ...incoming, pending: true }
 			runtime.clearSeededRunArgs(k, p)
 		})
 	})
@@ -228,6 +246,8 @@
 			{active}
 			embedded
 			{seededRun}
+			{seededByAgent}
+			onSeedApplied={() => held && (held = { ...held, pending: false })}
 			onClearSeededRun={() => (held = undefined)}
 			onLoadState={setLoadState}
 		/>
@@ -240,6 +260,8 @@
 			{active}
 			embedded
 			{seededRun}
+			{seededByAgent}
+			onSeedApplied={() => held && (held = { ...held, pending: false })}
 			onClearSeededRun={() => (held = undefined)}
 			onLoadState={setLoadState}
 		/>

frontend/src/lib/components/sessions/sessionRuntime.svelte.ts

@@ -637,8 +637,15 @@ function createRuntime(session: Session): SessionRuntime {
 				t.url.includes('version=')
 			)
 		})
-		if (pinned) previewTabs.navigate(viewTarget, pinned.id)
-		else previewTabs.open(viewTarget)
+		if (pinned) {
+			previewTabs.navigate(viewTarget, pinned.id)
+			// `navigate` re-points without bringing the tab forward, and the call is about to
+			// tell the reader the page is open — which it would not be, if they had switched
+			// away from it before asking.
+			previewTabs.select(pinned.id)
+		} else {
+			previewTabs.open(viewTarget)
+		}
 		return true
 	}
 	manager.closeRunForm = (toolCallId) => previewTabs.closeRunForm(toolCallId)