v0.247.0: i18n spike — the dashboard can speak English, Hungarian byte-identical

Message bundles (internal/i18n) expanded into templates before parsing, one
template set per language. Launcher, /backups, /apps/<slug> and the layout
converted; household language setting, POST /settings/language, ?lang= override,
report field. Parity test against fixtures captured from unconverted templates;
copy gates read templates expanded; new i18n_missing_gate.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/report/types.go

@@ -48,6 +48,11 @@ type Report struct {
 	// their own password). The hub ingests it SET-ONLY: a later false (wiped settings.json
 	// after DR) never un-claims the customer hub-side.
 	Claimed bool `json:"claimed"`
+
+	// Language (v0.247.0, i18n) — the household's dashboard language ("hu" | "en"), so the hub's
+	// customer e-mails can follow it (plan slice 3). Additive: the hub stores the raw report and no hub
+	// release reads it yet. Always present, never omitted: a box that never chose reports "hu".
+	Language string `json:"language"`
 }
 
 // SystemReport holds host-level system info.