fix(llm): user-friendly messages + settings link for all LLM errors

Move getUserMessage() to the base LlmError class so every error type
gets a German explanation with a clickable settings deep-link:

- TierTooLowError: "Kein KI-Modell aktiviert. Mindestens X benötigt."
- ProviderBlockedError: "… hat die Anfrage blockiert (Inhaltsfilter)."
- BackendUnreachableError: "… ist nicht erreichbar."
- EdgeLoadFailedError: "Browser-Modell konnte nicht geladen werden."
- Generic fallback: also includes the settings link now

The companion engine now catches LlmError (base class) instead of
only NoTierAvailableError, covering all failure modes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/mana/apps/web/src/lib/modules/companion/engine.ts

@@ -11,7 +11,7 @@
  * routes through text-completion).
  */
 
-import { llmOrchestrator, NoTierAvailableError } from '@mana/shared-llm';
+import { llmOrchestrator, LlmError } from '@mana/shared-llm';
 import { isLocalLlmSupported, getLocalLlmStatus, loadLocalLlm } from '@mana/local-llm';
 import { companionChatTask } from '$lib/llm-tasks/companion-chat';
 import { generateContextDocument } from '$lib/data/projections/context-document';
@@ -54,11 +54,11 @@ async function callLlm(messages: LlmMessage[], onToken?: (token: string) => void
 		});
 		return result.value.content;
 	} catch (err) {
-		if (err instanceof NoTierAvailableError) {
+		if (err instanceof LlmError) {
 			return err.getUserMessage();
 		}
 		const msg = err instanceof Error ? err.message : String(err);
-		return `LLM nicht verfügbar: ${msg}`;
+		return `LLM nicht verfügbar: ${msg}\n\n[KI-Einstellungen öffnen](/?app=settings#ai-options)`;
 	}
 }
 

packages/shared-llm/src/errors.ts

@@ -6,11 +6,18 @@
 
 import type { LlmTier } from './tiers';
 
+const SETTINGS_LINK = '[KI-Einstellungen öffnen](/?app=settings#ai-options)';
+
 export class LlmError extends Error {
 	constructor(message: string) {
 		super(message);
 		this.name = 'LlmError';
 	}
+
+	/** User-friendly German explanation with settings deep-link (Markdown). */
+	getUserMessage(): string {
+		return `${this.message}\n\n${SETTINGS_LINK}`;
+	}
 }
 
 /** Why a specific tier was skipped. */
@@ -88,11 +95,14 @@ export class TierTooLowError extends LlmError {
 		public readonly requiredTier: LlmTier,
 		public readonly userTier: LlmTier
 	) {
-		super(
-			`Task '${taskName}' requires tier '${requiredTier}' but user is on '${userTier}'. Activate the higher tier in settings.`
-		);
+		super(`Task '${taskName}' requires tier '${requiredTier}' but user is on '${userTier}'.`);
 		this.name = 'TierTooLowError';
 	}
+
+	getUserMessage(): string {
+		const needed = tierLabel(this.requiredTier);
+		return `Kein KI-Modell aktiviert. Mindestens **${needed}** wird benötigt.\n\n${SETTINGS_LINK}`;
+	}
 }
 
 /**
@@ -109,6 +119,10 @@ export class ProviderBlockedError extends LlmError {
 		super(`Provider '${tier}' blocked the request: ${providerMessage}`);
 		this.name = 'ProviderBlockedError';
 	}
+
+	getUserMessage(): string {
+		return `**${tierLabel(this.tier)}** hat die Anfrage blockiert (Inhaltsfilter). Versuche es mit einer anderen Formulierung oder wechsle den Anbieter.\n\n${SETTINGS_LINK}`;
+	}
 }
 
 /** Network/server error from a remote tier (mana-server, cloud). */
@@ -123,6 +137,10 @@ export class BackendUnreachableError extends LlmError {
 		);
 		this.name = 'BackendUnreachableError';
 	}
+
+	getUserMessage(): string {
+		return `**${tierLabel(this.tier)}** ist nicht erreichbar. Prüfe ob der Service läuft.\n\n${SETTINGS_LINK}`;
+	}
 }
 
 /**
@@ -134,4 +152,8 @@ export class EdgeLoadFailedError extends LlmError {
 		super(`Edge LLM failed to load: ${cause}`);
 		this.name = 'EdgeLoadFailedError';
 	}
+
+	getUserMessage(): string {
+		return `Browser-Modell konnte nicht geladen werden: ${this.cause}\n\n${SETTINGS_LINK}`;
+	}
 }