feat: add Google Search Console integration UI

Search Console page with overview cards, top queries/pages tables,
and query↔page drill-down. Integrations tab in Settings for
connect/disconnect flow. New Search tab in site navigation.

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ## [Unreleased]
 
+### Added
+
+- **Google Search Console integration.** Connect your Google Search Console account in Settings > Integrations to see which search queries bring visitors to your site. A new "Search" tab on your dashboard shows total clicks, impressions, average CTR, and average ranking position — with percentage changes compared to the previous period. Browse your top search queries and top pages in sortable, paginated tables. Click any query to see which pages rank for it, or click any page to see which queries drive traffic to it. Pulse only requests read-only access to your Search Console data, encrypts your Google credentials, and lets you disconnect and fully remove all search data at any time.
+- **Integrations tab in Settings.** A new "Integrations" section in your site settings is where you connect and manage external services. Google Search Console is the first integration available — more will follow.
+
 ### Improved
 
 - **Visit duration now works for single-page sessions.** Previously, if a visitor viewed only one page and left, the visit duration showed as "0s" because there was no second pageview to measure against. Pulse now tracks how long you actually spent on the page and reports real durations — even for single-page visits. This makes the Visit Duration metric, Journeys, and Top Paths much more accurate.