feat(search): P3.1 filters and multi-query merge

Native include/exclude domains, time_range, topic, exact_match, min_score,
and up to 4 queries fused with RRF. Honesty notes stay off the Warn/fail
path. Tavily keeps include_answer false and sets auto_parameters false.
Cache key is canonical JSON. CLI flags and skill recipe included.

cmd/sift/searchcmd.go

@@ -8,15 +8,35 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"strings"
 )
 
+type stringList []string
+
+func (s *stringList) String() string { return strings.Join(*s, ",") }
+func (s *stringList) Set(v string) error {
+	*s = append(*s, v)
+	return nil
+}
+
 func searchMain() {
 	fs := flag.NewFlagSet("search", flag.ContinueOnError)
 	fs.SetOutput(io.Discard)
 	k := fs.Int("k", 0, "result cap")
 	asJSON := fs.Bool("json", false, "native envelope")
+	var include, exclude stringList
+	fs.Var(&include, "include-domain", "restrict or prefer this host")
+	fs.Var(&exclude, "exclude-domain", "drop this host")
+	domainsMode := fs.String("domains-mode", "", "restrict|prefer")
+	timeRange := fs.String("time-range", "", "day|week|month|year")
+	startDate := fs.String("start-date", "", "YYYY-MM-DD")
+	endDate := fs.String("end-date", "", "YYYY-MM-DD")
+	topic := fs.String("topic", "", "general|news|finance")
+	exact := fs.Bool("exact-match", false, "require quoted phrases")
+	minScore := fs.Float64("min-score", 0, "Tavily score cut")
+	queriesFile := fs.String("queries-file", "", "JSON array of 1-4 queries")
 	args := os.Args[1:]
-	flagArgs, pos, err := splitAroundPositional(args, map[string]bool{"k": true})
+	flagArgs, pos, err := splitAroundPositional(args, searchValueFlags)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(2)
@@ -25,20 +45,65 @@ func searchMain() {
 		fmt.Fprintln(os.Stderr, searchUsage)
 		os.Exit(2)
 	}
-	if len(pos) != 1 {
-		fmt.Fprintln(os.Stderr, searchUsage)
-		os.Exit(2)
+	body := map[string]any{}
+	if *queriesFile != "" {
+		if len(pos) != 0 {
+			fmt.Fprintln(os.Stderr, searchUsage)
+			os.Exit(2)
+		}
+		raw, err := os.ReadFile(*queriesFile)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(2)
+		}
+		var qs []string
+		if err := json.Unmarshal(raw, &qs); err != nil {
+			fmt.Fprintln(os.Stderr, "queries-file: want JSON array of strings")
+			os.Exit(2)
+		}
+		body["queries"] = qs
+	} else {
+		if len(pos) != 1 {
+			fmt.Fprintln(os.Stderr, searchUsage)
+			os.Exit(2)
+		}
+		body["query"] = pos[0]
+	}
+	if *k > 0 {
+		body["k"] = *k
+	}
+	if len(include) > 0 {
+		body["include_domains"] = []string(include)
+	}
+	if len(exclude) > 0 {
+		body["exclude_domains"] = []string(exclude)
+	}
+	if *domainsMode != "" {
+		body["include_domains_mode"] = *domainsMode
+	}
+	if *timeRange != "" {
+		body["time_range"] = *timeRange
+	}
+	if *startDate != "" {
+		body["start_date"] = *startDate
+	}
+	if *endDate != "" {
+		body["end_date"] = *endDate
+	}
+	if *topic != "" {
+		body["topic"] = *topic
+	}
+	if *exact {
+		body["exact_match"] = true
+	}
+	if *minScore > 0 {
+		body["min_score"] = *minScore
 	}
-	query := pos[0]
 	base, key, err := loadClient()
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(5)
 	}
-	body := map[string]any{"query": query}
-	if *k > 0 {
-		body["k"] = *k
-	}
 	raw, _ := json.Marshal(body)
 	req, err := http.NewRequest(http.MethodPost, base+"/v1/search", bytes.NewReader(raw))
 	if err != nil {
@@ -80,7 +145,24 @@ func searchMain() {
 		if sn, _ := m["snippet"].(string); sn != "" {
 			fmt.Println(sn)
 		}
+		if d, _ := m["published_date"].(string); d != "" {
+			fmt.Println(d)
+		}
 	}
 }
 
-const searchUsage = `usage: sift search "<query>" [--k N] [--json]`
+var searchValueFlags = map[string]bool{
+	"k": true, "include-domain": true, "exclude-domain": true,
+	"domains-mode": true, "time-range": true, "start-date": true, "end-date": true,
+	"topic": true, "min-score": true, "queries-file": true,
+}
+
+const searchUsage = `usage: sift search "<query>" [--k n] [--json]
+            [--include-domain host]... [--exclude-domain host]...
+            [--domains-mode restrict|prefer]
+            [--time-range day|week|month|year]
+            [--start-date YYYY-MM-DD] [--end-date YYYY-MM-DD]
+            [--topic general|news|finance]
+            [--exact-match]
+            [--min-score 0.5]
+            [--queries-file path]`