Merge PR114 dictation foundation for approved provider-row finishing

Preserve original contributor commit 3bb28e5f29. Resolve only the settings-dialog conflict by retaining current General/update behavior: the donor General-only language placement is explicitly superseded by the human-approved row BELOW the full-width Deepgram key. The assigned implementation worker will implement that placement and approved shared dropdown finishing. Foundation only, not a checked candidate.

src/core/dictation.ts

@@ -0,0 +1,90 @@
+/** Nova-3 monolingual language codes, including documented locale aliases.
+ * Source: https://developers.deepgram.com/docs/models-languages-overview
+ * Multilingual is a separate mode; its supported language set differs.
+ */
+const NOVA_3_LANGUAGES = [
+	["Afrikaans", ["af", "af-ZA"]],
+	["Arabic", ["ar", "ar-AE", "ar-SA", "ar-QA", "ar-KW", "ar-SY", "ar-LB", "ar-PS", "ar-JO", "ar-EG", "ar-SD", "ar-TD", "ar-MA", "ar-DZ", "ar-TN", "ar-IQ", "ar-IR"]],
+	["Armenian", ["hy"]],
+	["Assamese", ["as", "as-IN"]],
+	["Belarusian", ["be"]],
+	["Bengali", ["bn"]],
+	["Bosnian", ["bs"]],
+	["Bulgarian", ["bg"]],
+	["Catalan", ["ca"]],
+	["Chinese (Cantonese, Traditional)", ["zh-HK"]],
+	["Chinese (Mandarin, Simplified)", ["zh", "zh-CN", "zh-Hans"]],
+	["Chinese (Mandarin, Traditional)", ["zh-TW", "zh-Hant"]],
+	["Croatian", ["hr"]],
+	["Czech", ["cs", "cs-CZ"]],
+	["Danish", ["da", "da-DK"]],
+	["Dutch", ["nl"]],
+	["English", ["en", "en-US", "en-AU", "en-GB", "en-IN", "en-NZ"]],
+	["Estonian", ["et"]],
+	["Finnish", ["fi"]],
+	["Flemish", ["nl-BE"]],
+	["French", ["fr", "fr-CA"]],
+	["Georgian", ["ka", "ka-GE"]],
+	["German", ["de"]],
+	["German (Switzerland)", ["de-CH"]],
+	["Greek", ["el"]],
+	["Gujarati", ["gu", "gu-IN"]],
+	["Hebrew", ["he"]],
+	["Hindi", ["hi"]],
+	["Hungarian", ["hu"]],
+	["Indonesian", ["id"]],
+	["Italian", ["it"]],
+	["Japanese", ["ja"]],
+	["Kannada", ["kn"]],
+	["Kazakh", ["kk", "kk-KZ"]],
+	["Korean", ["ko", "ko-KR"]],
+	["Latvian", ["lv"]],
+	["Lithuanian", ["lt"]],
+	["Macedonian", ["mk"]],
+	["Malay", ["ms"]],
+	["Marathi", ["mr"]],
+	["Mongolian", ["mn"]],
+	["Nepali", ["ne"]],
+	["Norwegian", ["no"]],
+	["Pashto", ["ps", "ps-AF"]],
+	["Persian", ["fa"]],
+	["Polish", ["pl"]],
+	["Portuguese", ["pt", "pt-BR", "pt-PT"]],
+	["Punjabi", ["pa", "pa-IN"]],
+	["Romanian", ["ro"]],
+	["Russian", ["ru"]],
+	["Serbian", ["sr"]],
+	["Slovak", ["sk"]],
+	["Slovenian", ["sl"]],
+	["Spanish", ["es", "es-419"]],
+	["Swedish", ["sv", "sv-SE"]],
+	["Tagalog", ["tl"]],
+	["Tamil", ["ta"]],
+	["Telugu", ["te"]],
+	["Thai", ["th", "th-TH"]],
+	["Turkish", ["tr", "tr-TR"]],
+	["Ukrainian", ["uk"]],
+	["Urdu", ["ur"]],
+	["Vietnamese", ["vi"]],
+] as const;
+
+export type DictationLanguage = "multi" | (typeof NOVA_3_LANGUAGES)[number][1][number];
+
+export const DICTATION_LANGUAGES: readonly { code: DictationLanguage; label: string }[] = [
+	{ code: "multi", label: "Multilingual" },
+	...NOVA_3_LANGUAGES.flatMap(([name, codes]) =>
+		codes.map((code, i) => ({ code, label: i === 0 ? name : `${name} (${code})` })),
+	).sort((a, b) => a.label.localeCompare(b.label, "en")),
+];
+
+export function isDictationLanguage(value: unknown): value is DictationLanguage {
+	return DICTATION_LANGUAGES.some(({ code }) => code === value);
+}
+
+/** Only language varies. Keep the owner's tuned streaming parameters. */
+export function deepgramListenUrl(language: DictationLanguage): string {
+	return "wss://api.deepgram.com/v1/listen" +
+		"?model=nova-3&encoding=linear16&sample_rate=16000&channels=1" +
+		"&smart_format=true&punctuate=true&endpointing=300" +
+		`&language=${encodeURIComponent(language)}`;
+}

src/core/index.ts

@@ -59,6 +59,7 @@ export * from "./fuzzy.ts";
 // the user-settings record's shape/sanitizer (pure) and its fully-resolved
 // view. Browser-safe — the Wave-4 panel imports these directly.
 export * from "./settings.ts";
+export * from "./dictation.ts";
 // graph-deletion.ts (wave 6): the whole module is PURE but storage-port
 // driven — the deletion RUNS server-side only. The shell needs exactly one
 // two type-only things from it: the ChatDeleteMode union (the delete

src/core/settings-resolution.ts

@@ -35,6 +35,7 @@ import {
 	type BackgroundModelRole,
 	type FactorySettings,
 	type GeneralSettings,
+	type DictationSettings,
 	type CompactionSettings,
 	type GraphSettings,
 	type ModelSlot,
@@ -69,6 +70,7 @@ export type EffectiveAppearance = FactorySettings["appearance"];
 /** The concrete view: every knob resolved, no absent fields. */
 export interface EffectiveSettings {
 	general: Required<GeneralSettings>;
+	dictation: Required<DictationSettings>;
 	agent: {
 		models: Record<BackgroundModelRole, EffectiveModelSpec | undefined>;
 		/** Delta map as stored — consumers resolve absent key → enabled. */
@@ -176,6 +178,9 @@ export function resolveSettings(record: UserSettings | null): EffectiveSettings
 		general: {
 			autoUpdate: record?.general?.autoUpdate ?? FACTORY_SETTINGS.general.autoUpdate,
 		},
+		dictation: {
+			language: record?.dictation?.language ?? FACTORY_SETTINGS.dictation.language,
+		},
 		agent: {
 			models,
 			tools: agent.tools ?? {},

src/core/settings.ts

@@ -32,6 +32,7 @@ import { AUTH_PROVIDER_KEYS } from "./auth-keys.ts";
 import type { ModelRole } from "../../config.ts";
 import type { ChatSettings } from "./contracts/chat.ts";
 import type { SearchEngineId } from "./search.ts";
+import { isDictationLanguage, type DictationLanguage } from "./dictation.ts";
 
 /** The schema version this code understands. Bump ONLY for breaking shape
  *  changes (a field renamed/meaning changed); pure additions never bump. */
@@ -235,6 +236,11 @@ export interface GeneralSettings {
 	autoUpdate?: boolean;
 }
 
+/** One app-wide dictation preference, shared by every composer. */
+export interface DictationSettings {
+	language?: DictationLanguage;
+}
+
 /** Agent settings — everything about the non-conversation machinery. */
 export interface AgentSettings {
 	/** Background-role model/thinking overrides (absent role = config pin). */
@@ -361,6 +367,7 @@ export interface CompactionSettings {
 export interface UserSettings {
 	version: number;
 	general?: GeneralSettings;
+	dictation?: DictationSettings;
 	agent?: AgentSettings;
 	/** The strong/cheap/vision model slots (model slots wave, 2026-09-20). */
 	models?: ModelsSettings;
@@ -378,6 +385,7 @@ export interface UserSettings {
 export interface FactorySettings {
 	version: number;
 	general: Required<GeneralSettings>;
+	dictation: Required<DictationSettings>;
 	appearance: {
 		mode: "dark" | "light";
 		background: string | null;
@@ -397,6 +405,7 @@ export interface FactorySettings {
 export const FACTORY_SETTINGS: FactorySettings = {
 	version: CURRENT_SETTINGS_VERSION,
 	general: { autoUpdate: true },
+	dictation: { language: "en" },
 	appearance: {
 		mode: "dark",
 		background: null, // the dark default (#141414) lives in the mode's derivation curve
@@ -615,6 +624,13 @@ export function sanitizeUserSettings(raw: unknown): UserSettings | null {
 	if (r.general !== null && typeof r.general === "object" && !Array.isArray(r.general)) {
 		out.general = sanitizeGeneral(r.general as Record<string, unknown>);
 	}
+	if (r.dictation !== undefined) {
+		const raw = r.dictation;
+		out.dictation = raw !== null && typeof raw === "object" && !Array.isArray(raw) &&
+			isDictationLanguage((raw as Record<string, unknown>).language)
+			? { language: (raw as DictationSettings).language }
+			: {};
+	}
 	if (r.agent !== null && typeof r.agent === "object" && !Array.isArray(r.agent)) {
 		out.agent = sanitizeAgent(r.agent as Record<string, unknown>);
 	}