fix(wing,server): client names are matched as whole Unicode words; unsafe lists are a startup error (review of #214)

- WrapNames bounds the bare name list with Unicode-aware edges instead of \b
  (Go's \b is ASCII-only, so a name with a non-ASCII edge letter such as Åke,
  Société, Ørsted would never have matched), and validates the list on its own:
  it must compile, must not match the empty string, and cannot break out of its
  group ('x)|.*(' compiles alone only if balanced)
- NewRouter refuses any pattern that matches text naming no client
- docs state the whole-word semantics and what is not matched
Mutation-checked. Open decision for Mathias: whole-word versus substring recall
for a confidentiality filter (plurals, CamelCase and digits glued on do not match).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ingestion/cmd/server/main.go

@@ -152,17 +152,18 @@ func envInt(key string, fallback int) int {
 
 // ingestClientPattern picks the client-content pattern for raw/ routing.
 // INGEST_CLIENT_BLOCK is a complete regexp and is used as is. Otherwise the
-// shared CLAUDE_INGEST_CLIENT_BLOCK is used, which the deployment injects as a
-// bare alternation of client names that claudewatcher wraps in \b(...)\b: it is
-// wrapped the same way here, or a short name would match inside ordinary words.
-func ingestClientPattern(getenv func(string) string) string {
+// shared CLAUDE_INGEST_CLIENT_BLOCK is used: the deployment injects it as a bare
+// list of client names (regexp alternation), which wing.WrapNames bounds so a
+// short name does not match inside ordinary words, and which it refuses if it
+// would break out of its group or match the empty string.
+func ingestClientPattern(getenv func(string) string) (string, error) {
 	if p := getenv("INGEST_CLIENT_BLOCK"); p != "" {
-		return p
+		return p, nil
 	}
 	if names := getenv("CLAUDE_INGEST_CLIENT_BLOCK"); names != "" {
-		return `\b(` + names + `)\b`
+		return wing.WrapNames(names)
 	}
-	return ""
+	return "", nil
 }
 
 // envFlag reads a boolean switch. Unset is off; a value strconv.ParseBool does
@@ -441,7 +442,11 @@ func main() {
 			os.Exit(1)
 		}
 		if routing {
-			pattern := ingestClientPattern(os.Getenv)
+			pattern, perr := ingestClientPattern(os.Getenv)
+			if perr != nil {
+				logger.Error("client-content pattern", "err", perr)
+				os.Exit(1)
+			}
 			router, rerr := wing.NewRouter(brainDir, envOr("INGEST_DEFAULT_WING", "web-clip"), pattern)
 			if rerr != nil {
 				logger.Error("build wing router", "err", rerr)