feat: minify JSON output when --json flag is used

Output compact JSON (no whitespace) in --json mode to save tokens
when piped to AI agents. Closes #6

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: VinciGit00

README.md

@@ -86,7 +86,7 @@ JUST_SCRAPE_DEBUG=1 just-scrape ...  # Debug logging to stderr
 
 ## JSON Mode (`--json`)
 
-All commands support `--json` for machine-readable output. When set, banner, spinners, and interactive prompts are suppressed — only raw JSON on stdout.
+All commands support `--json` for machine-readable output. When set, banner, spinners, and interactive prompts are suppressed — only minified JSON on stdout (saves tokens when piped to AI agents).
 
 ```bash
 just-scrape credits --json | jq '.remaining_credits'

src/lib/log.ts

@@ -30,7 +30,7 @@ export function create(quiet = false) {
 			if (!quiet) s.message(`Status: ${status}`);
 		},
 		result(data: unknown) {
-			if (quiet) console.log(JSON.stringify(data, null, 2));
+			if (quiet) console.log(JSON.stringify(data));
 			else console.log(`\n${highlight(JSON.stringify(data, null, 2))}\n`);
 		},
 		error(message?: string) {