feat: prefetch all folder script assets so graph is stable on load

On pipeline load, eagerly infer body assets for every persisted folder
script and seed the existing inferredWritesByPath overlay, instead of
only filling it when a node is selected. Scripts whose persisted asset
rows are missing (e.g. object-form writeS3File) now have their edges
from first paint, so clicking a node no longer re-layouts the graph.
One-shot per (workspace, base-graph) load, untracked map reads,
generation-cancelled, pool-capped fetches.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/routes/(root)/(logged)/pipeline/[folder]/+page.svelte

@@ -53,7 +53,7 @@
 	import { fade } from 'svelte/transition'
 	import Popover from '$lib/components/meltComponents/Popover.svelte'
 	import HideButton from '$lib/components/apps/editor/settingsPanel/HideButton.svelte'
-	import { inferArgs } from '$lib/infer'
+	import { inferArgs, inferAssets } from '$lib/infer'
 
 	// Variables and resources are declarative config, not pipeline assets —
 	// they're hub-shaped (referenced by most runnables) and would swamp the
@@ -1083,6 +1083,64 @@
 		}
 	)
 
+	// On pipeline load, eagerly infer body assets for EVERY persisted script
+	// in the folder and seed the same `inferredWritesByPath` overlay the
+	// open-script live path uses. Without this, a script whose persisted
+	// asset rows are missing (e.g. object-form writeS3File the server parser
+	// didn't extract) has no edges until you click it — which visibly
+	// re-layouts the graph. Doing it up-front makes the graph complete and
+	// layout-stable from first paint, independent of the stale `asset` table.
+	//
+	// One-shot per (workspace, base-graph) load — deps are only those; the
+	// drafts/inferred maps are read via `untrack` so a keystroke or a new
+	// draft doesn't re-trigger the sweep. Generation token cancels a stale
+	// sweep if the folder/graph changes mid-flight. Pool-capped fetches.
+	let assetPrefetchGen = 0
+	$effect(() => {
+		const ws = $workspaceStore
+		const g = graphRes.current
+		if (!ws || !g) return
+		const gen = ++assetPrefetchGen
+		const targets = untrack(() =>
+			g.runnables
+				.filter((r) => r.usage_kind === 'script')
+				.map((r) => r.path)
+				.filter((p) => !drafts.has(p) && !inferredWritesByPath.has(p))
+		)
+		if (targets.length === 0) return
+		let i = 0
+		const POOL = 6
+		const worker = async () => {
+			while (i < targets.length && gen === assetPrefetchGen) {
+				const path = targets[i++]
+				try {
+					const s = await ScriptService.getScriptByPath({ workspace: ws, path })
+					if (gen !== assetPrefetchGen) return
+					const res = await inferAssets(s.language, s.content ?? '')
+					if (gen !== assetPrefetchGen) return
+					const writes = ((res?.assets ?? []) as AssetWithAltAccessType[])
+						.filter((a) => {
+							const at = a.access_type ?? a.alt_access_type
+							return at === 'w' || at === 'rw'
+						})
+						.map((a) => ({ kind: a.kind, path: a.path }))
+					if (writes.length > 0) {
+						untrack(() => {
+							// A live edit / prior sweep may have filled it meanwhile.
+							if (inferredWritesByPath.has(path)) return
+							const next = new Map(inferredWritesByPath)
+							next.set(path, writes)
+							inferredWritesByPath = next
+						})
+					}
+				} catch {
+					// Skip — that node just falls back to base-graph edges.
+				}
+			}
+		}
+		for (let k = 0; k < Math.min(POOL, targets.length); k++) void worker()
+	})
+
 	function pluralize(n: number, singular: string): string {
 		return `${n} ${singular}${n === 1 ? '' : 's'}`
 	}