refactor: switch the whole project to English

talk is going to be published. Code comments, CLI output, error messages,
daemon log lines, MCP descriptions and results, test names and assertions,
README, spec, skill, build scripts and flake are now English. Only the
spoken announcement texts stay bilingual: the wrap result and the test
sentence are German or English depending on the detected language.

Language fallback is now configurable: `lang = "en" | "de"` (env
TALK_LANG, default en) is used when detection cannot tell (numbers, single
words, ties) and for talk's own announcements. langdetect.Detect takes the
fallback as an argument instead of hard-coding German. `talk setup` asks for
it; `talk doctor` and `talk status` show it.

Vocabulary pinned across packages so the process-boundary tests observe
stable strings: chain log lines ("chain: tier X skipped (not available)",
"falling back to the next tier", "spoken via X"), queue lines ("discarded:
quiet hours ... active", "replaced by toast", "max_age"), CLI notes
("speaking directly", "daemon started at", "no daemon", "nothing to cancel"),
status block with aligned English labels, MCP messages, origin guard 403.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/provider/catalog.go

@@ -2,10 +2,10 @@ package provider
 
 import "sort"
 
-// Voice ist ein Eintrag des Stimmen-Katalogs: eine bekannte Stimme eines
-// Providers für eine Sprache, mit lesbarem Namen. Der Katalog ist kuratiert
-// (die gängigen Standardstimmen), nicht vollständig — jede Voice-ID des
-// Providers funktioniert auch ohne Katalog-Eintrag (--voice, config).
+// Voice is an entry of the voice catalog: a known voice of a provider for a
+// language, with a readable name. The catalog is curated (the common
+// standard voices), not complete; any voice ID of the provider also works
+// without a catalog entry (--voice, config).
 type Voice struct {
 	Provider string
 	Lang     string // de | en
@@ -13,10 +13,10 @@ type Voice struct {
 	Name     string
 }
 
-// catalog sind die bekannten Stimmen je Provider. ElevenLabs: öffentliche
-// Premade-Stimmen (multilingual, daher für de UND en gelistet). OpenAI: die
-// Stimmen der TTS-API (sprachunabhängig). Edge: Neural-Stimmen der
-// jeweiligen Locale. osbuiltin kennt keine IDs (das OS wählt).
+// catalog lists the known voices per provider. ElevenLabs: public premade
+// voices (multilingual, hence listed for both de AND en). OpenAI: the voices
+// of the TTS API (language independent). Edge: neural voices of the
+// respective locale. osbuiltin has no IDs (the OS chooses).
 var catalog = []Voice{
 	{"elevenlabs", "de", "21m00Tcm4TlvDq8ikWAM", "Rachel"},
 	{"elevenlabs", "de", "pNInz6obpgDQGcFmaJgB", "Adam"},
@@ -54,8 +54,8 @@ var catalog = []Voice{
 	{"edge", "en", "en-GB-RyanNeural", "Ryan (GB)"},
 }
 
-// Catalog liefert den Stimmen-Katalog in stabiler Reihenfolge
-// (Ketten-Reihenfolge der Provider, dann de vor en, dann Katalog-Reihe).
+// Catalog returns the voice catalog in stable order (chain order of the
+// providers, then de before en, then catalog order).
 func Catalog() []Voice {
 	out := make([]Voice, len(catalog))
 	copy(out, catalog)
@@ -72,7 +72,7 @@ func Catalog() []Voice {
 	return out
 }
 
-// VoiceName liefert den Katalog-Namen einer Voice-ID; leer, wenn unbekannt.
+// VoiceName returns the catalog name of a voice ID; empty if unknown.
 func VoiceName(provider, id string) string {
 	for _, v := range catalog {
 		if v.Provider == provider && v.ID == id {
@@ -82,9 +82,9 @@ func VoiceName(provider, id string) string {
 	return ""
 }
 
-// DefaultVoice liefert die effektive Default-Stimme eines Providers für
-// eine Sprache: config-Mapping voice.<provider>.<lang> vor dem Repo-Default
-// (ohne --voice-Pin). Leer bei osbuiltin (das OS wählt).
+// DefaultVoice returns the effective default voice of a provider for a
+// language: config mapping voice.<provider>.<lang> before the repo default
+// (without a --voice pin). Empty for osbuiltin (the OS chooses).
 func DefaultVoice(provider, lang string, cfgVoices map[string]map[string]string) string {
 	return resolveVoice(provider, lang, "", cfgVoices[provider])
 }