add TUI validation for language-model compatibility on save

internal/tui/configure_transcription.go

@@ -156,6 +156,43 @@ func editTranscription(cfg *config.Config, configuredProviders []string) ([]stri
 		return configuredProviders, err
 	}
 
+	// validate language-model compatibility before saving
+	registryName = mapConfigProviderToRegistry(selectedProvider)
+	if err := provider.ValidateModelLanguage(registryName, selectedModel, selectedLanguage); err != nil {
+		// show error dialog and let user fix
+		fmt.Println()
+		fmt.Println(StyleError.Render("Language-Model Incompatibility"))
+		fmt.Println(StyleMuted.Render(err.Error()))
+		fmt.Println()
+		fmt.Println(StyleMuted.Render("You can:"))
+		fmt.Println(StyleMuted.Render("  - Change to a different model"))
+		fmt.Println(StyleMuted.Render("  - Select 'Auto-detect' for language"))
+		fmt.Println(StyleMuted.Render("  - Choose a supported language"))
+		fmt.Println()
+
+		var retry bool
+		retryForm := huh.NewForm(
+			huh.NewGroup(
+				huh.NewConfirm().
+					Title("Try again?").
+					Description("Return to fix the incompatibility").
+					Affirmative("Yes, let me fix it").
+					Negative("Cancel").
+					Value(&retry),
+			),
+		).WithTheme(getTheme())
+
+		if err := retryForm.Run(); err != nil {
+			return configuredProviders, err
+		}
+
+		if retry {
+			// recurse to let user fix the issue
+			return editTranscription(cfg, configuredProviders)
+		}
+		return configuredProviders, nil
+	}
+
 	// for whisper-cpp, check if model needs download
 	if selectedProvider == "whisper-cpp" && !whisper.IsInstalled(selectedModel) {
 		modelInfo := whisper.GetModel(selectedModel)

progress.txt

@@ -298,3 +298,12 @@ Started: Sun Feb  1 12:22:47 AM CET 2026
 - Language code saved to config, not display name
 - All 57 languages + Auto = 58 options total
 - All tests passing, typecheck passes
+
+### Task 30: Add TUI validation for language-model compatibility on save
+- Added validation check in `editTranscription()` before saving config
+- Uses `provider.ValidateModelLanguage(registryName, selectedModel, selectedLanguage)`
+- If validation fails: shows error with message and options (change model, select auto-detect, choose supported language)
+- Shows confirm dialog "Try again?" - if yes, recursively calls `editTranscription()` to let user fix
+- Config only saved AFTER validation passes (no save on cancel)
+- Leverages existing `ValidateModelLanguage` which returns error with supported languages list
+- All tests passing, typecheck passes

tasks/prd.jsonc

@@ -702,19 +702,19 @@
 				"User can fix by: changing model, changing language to auto, or changing to supported language",
 				"After showing error, return to the form so user can make changes"
 			],
-			"verify": [
+		"verify": [
-				"Selecting English-only model + Spanish language shows error on save",
+			"Selecting English-only model + Spanish language shows error on save",
-				"Error dialog displays clear message with options",
+			"Error dialog displays clear message with options",
-				"Config is not saved when validation fails",
+			"Config is not saved when validation fails",
-				"User can change model and save successfully",
+			"User can change model and save successfully",
-				"User can change language to auto and save successfully",
+			"User can change language to auto and save successfully",
-				"User can change language to supported language and save successfully",
+			"User can change language to supported language and save successfully",
-				"Typecheck passes"
+			"Typecheck passes"
-			],
+		],
-			"passes": false
+		"passes": true
-		},
+	},
-		// ============================================================================
+	// ============================================================================
-		// PHASE 7: STREAMING ADAPTER IMPLEMENTATIONS
+	// PHASE 7: STREAMING ADAPTER IMPLEMENTATIONS
 		// Each adapter is a separate task for right-sizing
 		// ============================================================================
 		{