refactor!: make addrkit a multi-city address normalizer

- remove the events/outages module, ArcGIS adapter, portal config and event statuses
- add a configurable city dictionary/parser and make City part of StreetKey
- seed: read city/city_name, namespace IDs by city, keep structures distinct
- fix reliability: schema v2 with fail-closed load, deterministic ordering,
  input limits, config validation, atomic DB publish, LLM response caps
- add read-only shadow mode comparing the old ES path with addrkit
- breaking: registry.db must be re-seeded; config has no portal section

internal/adapters/llm/rewriter.go

@@ -14,10 +14,12 @@ import (
 	_ "embed"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"regexp"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"git.totmin.ru/en2zmax/addrkit/internal/config"
 )
@@ -128,7 +130,9 @@ func (r *Rewriter) Rewrite(ctx context.Context, raw string) ([]string, error) {
 	}
 
 	var cr chatResponse
-	if err := json.NewDecoder(resp.Body).Decode(&cr); err != nil {
+	// Bound the reply: a broken or hostile model must not be able to stream an
+	// unbounded JSON body into the service.
+	if err := json.NewDecoder(io.LimitReader(resp.Body, 1<<20)).Decode(&cr); err != nil {
 		return nil, fmt.Errorf("decode llm response: %w", err)
 	}
 	if len(cr.Choices) == 0 {
@@ -154,8 +158,15 @@ func parseVariants(content string) []string {
 	}
 	out := make([]string, 0, len(parsed.Variants))
 	for _, v := range parsed.Variants {
-		if s := strings.TrimSpace(v); s != "" {
-			out = append(out, s)
+		s := strings.TrimSpace(v)
+		// A variant is a short address; the cap also keeps a hostile model
+		// from making the resolver scan a megabyte-long token.
+		if s == "" || utf8.RuneCountInString(s) > 512 {
+			continue
+		}
+		out = append(out, s)
+		if len(out) == 3 {
+			break
 		}
 	}
 	return out