fix(ui): add ic-btn-reset CSS + auto-convert auth.json to cookies.txt

- layout.css: add button.ic-btn-reset rule so all icon buttons
  (bell, back, close, retry, etc.) get proper background:none reset
  instead of browser-default white/grey appearance in dark mode
- instagram-extractor.ts: auto-convert secrets/auth.json
  (Playwright storage format) to Netscape cookies.txt at runtime
  whenever auth.json is newer; ensures sessionid and all Instagram
  session cookies are passed to yt-dlp, fixing empty media response

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/lib/server/instagram-extractor.ts

@@ -9,7 +9,7 @@
 
 import { execFile } from 'node:child_process';
 import { promisify } from 'node:util';
-import { existsSync } from 'node:fs';
+import { existsSync, readFileSync, writeFileSync, statSync } from 'node:fs';
 import { logError } from './utils/logger';
 import type { ExtractedContent, ProgressCallback } from './extraction';
 
@@ -20,9 +20,60 @@ const IMAGE_FETCH_TIMEOUT_MS = 10_000;
 const USER_AGENT =
 	'Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1';
 
+const AUTH_PATHS = ['/app/secrets/auth.json', './secrets/auth.json'];
 const COOKIE_PATHS = ['/app/secrets/cookies.txt', './secrets/cookies.txt'];
 
+interface PlaywrightCookie {
+	name: string;
+	value: string;
+	domain: string;
+	path: string;
+	expires: number;
+	httpOnly?: boolean;
+	secure?: boolean;
+}
+
+/** Convert Playwright auth.json → Netscape cookies.txt next to it. */
+function maybeConvertAuthJson(): void {
+	for (let i = 0; i < AUTH_PATHS.length; i++) {
+		const authPath = AUTH_PATHS[i];
+		const cookiePath = COOKIE_PATHS[i];
+		if (!existsSync(authPath)) continue;
+
+		// Re-generate whenever auth.json is newer than the existing cookies.txt
+		const authMtime = statSync(authPath).mtimeMs;
+		const cookieMtime = existsSync(cookiePath) ? statSync(cookiePath).mtimeMs : 0;
+		if (cookieMtime >= authMtime) continue;
+
+		try {
+			const auth = JSON.parse(readFileSync(authPath, 'utf8')) as {
+				cookies?: PlaywrightCookie[];
+			};
+			const cookies: PlaywrightCookie[] = auth.cookies ?? [];
+			const lines = [
+				'# Netscape HTTP Cookie File',
+				'# Auto-generated from auth.json by InstaChef.',
+				''
+			];
+			for (const c of cookies) {
+				const domain = c.domain.startsWith('.') ? c.domain : `.${c.domain}`;
+				const includeSubdomains = 'TRUE';
+				const secure = c.secure ? 'TRUE' : 'FALSE';
+				const expiry = Math.floor(c.expires > 0 ? c.expires : 0);
+				lines.push(
+					[domain, includeSubdomains, c.path ?? '/', secure, expiry, c.name, c.value].join('\t')
+				);
+			}
+			writeFileSync(cookiePath, lines.join('\n') + '\n', 'utf8');
+		} catch {
+			// Non-fatal: yt-dlp will just run without cookies
+		}
+		break;
+	}
+}
+
 function resolveCookiePath(): string | null {
+	maybeConvertAuthJson();
 	for (const p of COOKIE_PATHS) {
 		if (existsSync(p)) return p;
 	}

src/routes/layout.css

@@ -99,7 +99,8 @@ html, body {
 }
 .ic-scroll::-webkit-scrollbar { display: none; }
 
-button.ic-btn {
+button.ic-btn,
+button.ic-btn-reset {
   background: none;
   border: 0;
   padding: 0;