feat(dashboard): Stream Error Patterns editor on provider page

Per-provider textarea (one pattern per line: plain text or /regex/flags)
saved via /api/settings as streamErrorPatterns. Mirrors the existing
providerTimeouts load/save pattern.

src/app/(dashboard)/dashboard/providers/[id]/page.js

@@ -96,6 +96,7 @@ export default function ProviderDetailPage() {
 	const [providerStickyLimit, setProviderStickyLimit] = useState("");
 	const [thinkingMode, setThinkingMode] = useState("auto");
 	const [providerTimeout, setProviderTimeout] = useState("");
+	const [streamErrorPatternsText, setStreamErrorPatternsText] = useState("");
 	const [autoPing, setAutoPing] = useState({ enabled: false, connections: {} });
 	const [suggestedModels, setSuggestedModels] = useState([]);
 	const [liveModels, setLiveModels] = useState([]);
@@ -444,6 +445,12 @@ export default function ProviderDetailPage() {
 			setProviderTimeout(
 				timeoutCfg.timeoutMs != null ? String(timeoutCfg.timeoutMs) : "",
 			);
+			// Load per-provider stream error patterns (one per line)
+			setStreamErrorPatternsText(
+				((settingsData.streamErrorPatterns || {})[providerId] || []).join(
+					"\n",
+				),
+			);
 			const autoPingSettingsKey = AUTO_PING_SETTINGS_KEYS[providerId];
 			const apCfg = autoPingSettingsKey
 				? settingsData[autoPingSettingsKey] || {}
@@ -595,6 +602,30 @@ export default function ProviderDetailPage() {
 		}
 	};
 
+	const saveStreamErrorPatterns = async () => {
+		try {
+			const settingsRes = await fetch("/api/settings", {
+				cache: "no-store",
+			});
+			const settingsData = settingsRes.ok ? await settingsRes.json() : {};
+			const current = settingsData.streamErrorPatterns || {};
+			const updated = { ...current };
+			const lines = streamErrorPatternsText
+				.split("\n")
+				.map((s) => s.trim())
+				.filter(Boolean);
+			if (lines.length > 0) updated[providerId] = lines;
+			else delete updated[providerId];
+			await fetch("/api/settings", {
+				method: "PATCH",
+				headers: { "Content-Type": "application/json" },
+				body: JSON.stringify({ streamErrorPatterns: updated }),
+			});
+		} catch (error) {
+			console.log("Error saving stream error patterns:", error);
+		}
+	};
+
 	const handleTimeoutChange = (value) => {
 		const cleaned = value.replace(/[^0-9]/g, "");
 		setProviderTimeout(cleaned);
@@ -2459,6 +2490,38 @@ export default function ProviderDetailPage() {
 				</Card>
 			)}
 
+			{/* Stream Error Patterns */}
+			<Card>
+				<div className="mb-3">
+					<h2 className="text-lg font-semibold">Stream Error Patterns</h2>
+					<p className="mt-1 text-sm text-text-muted">
+						Treat HTTP-200 streams whose first bytes match one of these
+						patterns as failed requests (enables fallback + FAILED logs). One
+						pattern per line: plain text (case-insensitive substring) or{" "}
+						<code className="rounded bg-background px-1 py-0.5 font-mono text-xs">
+							/regex/flags
+						</code>
+						. Only the first few KB of the stream are scanned.
+					</p>
+				</div>
+				<textarea
+					value={streamErrorPatternsText}
+					onChange={(e) => setStreamErrorPatternsText(e.target.value)}
+					rows={5}
+					placeholder={"server_error\n/network connection lost/i"}
+					className="w-full rounded-md border border-border bg-background p-2 font-mono text-xs focus:border-primary focus:outline-none"
+				/>
+				<div className="mt-2">
+					<Button
+						size="sm"
+						onClick={saveStreamErrorPatterns}
+						className="w-full sm:w-auto"
+					>
+						Save Patterns
+					</Button>
+				</div>
+			</Card>
+
 			{/* Models */}
 			<Card>
 				<div className="mb-4 flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">