Migrate to normalized FK schema (domain_host, domain_tld)

Replace source_host column with proper FK to domains table using
composite key (domain_host, domain_tld). This enables JOIN queries
instead of string concatenation for domain lookups.

Changes:
- Update Feed struct: SourceHost/TLD → DomainHost/DomainTLD
- Update all SQL queries to use domain_host/domain_tld columns
- Add column aliases (as source_host) for API backwards compatibility
- Update trigram index from source_host to domain_host
- Add getDomainHost() helper for extracting host from domain

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

crawler.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -42,16 +43,35 @@ func NewCrawler(connString string) (*Crawler, error) {
 		return nil, fmt.Errorf("failed to open database: %v", err)
 	}
 
+	// Custom transport with longer timeouts (HTTP/2 disabled for compatibility)
+	transport := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			MinVersion: tls.VersionTLS12,
+			NextProtos: []string{"http/1.1"}, // Force HTTP/1.1 for compatibility
+		},
+		DialContext: (&net.Dialer{
+			Timeout:   30 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext,
+		ForceAttemptHTTP2:     false,
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   30 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+		ResponseHeaderTimeout: 60 * time.Second,
+	}
+
 	return &Crawler{
 		MaxDepth:        10,
 		MaxPagesPerHost: 10,
-		Timeout:         10 * time.Second,
-		UserAgent:       "FeedCrawler/1.0",
+		Timeout:         60 * time.Second,
+		UserAgent:       "Mozilla/5.0 (compatible; FeedCrawler/1.0; +https://1440.news)",
 		startTime:       time.Now(),
 		db:              db,
 		shutdownCh:      make(chan struct{}),
 		client: &http.Client{
-			Timeout: 10 * time.Second,
+			Timeout:   60 * time.Second,
+			Transport: transport,
 			CheckRedirect: func(req *http.Request, via []*http.Request) error {
 				if len(via) >= 10 {
 					return fmt.Errorf("stopped after 10 redirects")
@@ -347,7 +367,7 @@ type FeedInfo struct {
 func (c *Crawler) getFeedInfo(feedURL string) *FeedInfo {
 	var title, description, siteURL, sourceHost *string
 	err := c.db.QueryRow(`
-		SELECT title, description, site_url, source_host FROM feeds WHERE url = $1
+		SELECT title, description, site_url, domain_host || '.' || domain_tld as source_host FROM feeds WHERE url = $1
 	`, feedURL).Scan(&title, &description, &siteURL, &sourceHost)
 	if err != nil {
 		return nil
@@ -363,7 +383,7 @@ func (c *Crawler) getFeedInfo(feedURL string) *FeedInfo {
 // RefreshAllProfiles updates profiles for all existing accounts with feed URLs
 func (c *Crawler) RefreshAllProfiles(publisher *Publisher, feedPassword string) {
 	rows, err := c.db.Query(`
-		SELECT url, title, description, site_url, source_host, publish_account
+		SELECT url, title, description, site_url, domain_host || '.' || domain_tld as source_host, publish_account
 		FROM feeds
 		WHERE publish_account IS NOT NULL AND publish_account <> ''
 	`)