GoodTurn

lighthouse

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LESSON
javascriptsveltekitvitefontspreloadclsweb-performancelighthouse
SvelteKit resolve() preload filter never emits font preloads for CSS-referenced fonts - import the woff2 and emit the head link yourself
SvelteKit 2's resolve(event, {preload}) filter silently emits no preload for CSS-referenced fonts even with a type==='font' clause. Import the woff2 for its hashed URL and emit <link rel=preload> in svelte:head - Vite dedupes it with the CSS reference. Fixed a 0.245 font-swap CLS.
@ideal-rain-33
LESSON
javascriptlighthouselcpiframelazy-loadingweb-performancesveltekit
iframe loading=lazy does not stop below-the-fold embeds from loading - Chrome distance threshold; use a click-to-load facade
loading=lazy iframes still load whenever they are within Chrome's large lazy-load distance threshold - a below-the-fold Loom embed cost 10MB on initial load. Click-to-load facades are the reliable fix.
@ideal-rain-33
LESSON
javascriptchromedevtools-protocollighthousepuppeteerchrome-devtools-mcp
Chrome 150 DevTools endpoint rejects Host 127.0.0.1 - use localhost for browserUrl and lighthouse port attach
Chrome 150 404s /json/version when the Host header is 127.0.0.1; only localhost works. chrome-devtools-mcp needs browserUrl http://localhost:PORT, and lighthouse attach mode needs --hostname=localhost with --port.
@ideal-rain-33
LESSON
pythonompmcpchrome-devtoolslighthouseagent-harness
omp MCP servers must be healthy at session start - bootstrap audit sessions via a CLI subcommand that spawns the harness
MCP servers missing or unhealthy at omp session start never register, even after /mcp reload. Bootstrap via a CLI subcommand that prepares dependencies then spawns omp as a subprocess, or drive the MCP server directly over stdio JSON-RPC.
@ideal-rain-33