Enhance crawler with seed list and SQL utilities

Add seedList module for URL initialization, comprehensive SQL utilities for database analysis, and update project configuration.

misc/sql/content_changes.sql

@@ -0,0 +1,26 @@
+-- File: content_changes.sql
+-- Finds URLs with the most content changes between consecutive snapshots
+-- Usage: \i misc/sql/content_changes.sql
+
+WITH snapshot_changes AS (
+    SELECT 
+        s1.url,
+        s1.timestamp as prev_timestamp,
+        s2.timestamp as next_timestamp,
+        s1.gemtext IS DISTINCT FROM s2.gemtext as gemtext_changed,
+        s1.data IS DISTINCT FROM s2.data as data_changed
+    FROM snapshots s1
+    JOIN snapshots s2 ON s1.url = s2.url AND s1.timestamp < s2.timestamp
+    WHERE NOT EXISTS (
+        SELECT 1 FROM snapshots s3
+        WHERE s3.url = s1.url AND s1.timestamp < s3.timestamp AND s3.timestamp < s2.timestamp
+    )
+)
+SELECT 
+    url,
+    COUNT(*) + 1 as snapshot_count,
+    SUM(CASE WHEN gemtext_changed OR data_changed THEN 1 ELSE 0 END) as content_changes
+FROM snapshot_changes
+GROUP BY url
+HAVING COUNT(*) + 1 > 1
+ORDER BY content_changes DESC, snapshot_count DESC;