fix: enable request interception when Fetch.enable is called (#50)

Fetch.enable was setting page.intercept_enabled to false and clearing
intercept_block_patterns, which caused should_block_url() to always
return false. As a result, Fetch.requestPaused events were never
triggered and Playwright's page.route() handlers never executed.

- Set intercept_enabled to true (was false)
- Propagate URL patterns to page.intercept_block_patterns (was cleared)

Fixes #49

Co-authored-by: Claude Opus 4.7 (1M context) <[email protected]>

crates/obscura-cdp/src/domains/fetch.rs

@@ -82,8 +82,8 @@ pub async fn handle(
             ctx.fetch_intercept.patterns = patterns.clone();
             let tx_clone = ctx.intercept_tx.clone();
             if let Some(page) = ctx.get_session_page_mut(session_id) {
-                page.intercept_enabled = false;
-                page.intercept_block_patterns.clear();
+                page.intercept_enabled = true;
+                page.intercept_block_patterns = patterns.clone();
                 if let Some(tx) = tx_clone {
                     page.set_intercept_tx(tx);
                 }