diff --git a/src/components/dm/GenerationHistory.astro b/src/components/dm/GenerationHistory.astro
index 3e67369..35c77b6 100644
--- a/src/components/dm/GenerationHistory.astro
+++ b/src/components/dm/GenerationHistory.astro
@@ -251,7 +251,7 @@ const { tier, userId } = Astro.props;
     );
   }
 
-  async function fetchProHistory(userId: number): Promise<HistoryItem[]> {
+  async function fetchProHistory(): Promise<HistoryItem[]> {
     const response = await fetch(`/api/dm/ai/history?limit=${MAX_HISTORY}`);
     if (!response.ok) {
       if (response.status === 401) {
@@ -269,7 +269,7 @@ const { tier, userId } = Astro.props;
     const loadingEl = container.querySelector<HTMLDivElement>('#history-loading');
 
     let items: HistoryItem[] = [];
-    let activeId: number | null = null;
+    const activeId: number | null = null;
 
     function showLoading() {
       loadingEl?.classList.remove('hidden');
@@ -283,7 +283,7 @@ const { tier, userId } = Astro.props;
       if (tier === 'pro' && userId) {
         showLoading();
         try {
-          items = await fetchProHistory(userId);
+          items = await fetchProHistory();
         } catch {
           items = [];
         } finally {
diff --git a/src/components/dm/InitiativeTracker.astro b/src/components/dm/InitiativeTracker.astro
index 1d978e0..77ba27b 100644
--- a/src/components/dm/InitiativeTracker.astro
+++ b/src/components/dm/InitiativeTracker.astro
@@ -184,7 +184,6 @@ const { tier = 'free', userId } = Astro.props;
 
   let activeIndex = 0;
   let currentSessionId: number | null = null;
-  let currentSessionName = '';
 
   interface CombatantData {
     id: string;
@@ -559,7 +558,6 @@ const { tier = 'free', userId } = Astro.props;
       saveCombatants(session.participants);
       activeIndex = 0;
       currentSessionId = session.id;
-      currentSessionName = session.name;
       if (sessionNameInput) sessionNameInput.value = session.name;
       updateVisibility();
       renderList();
@@ -578,7 +576,6 @@ const { tier = 'free', userId } = Astro.props;
     const result = await apiSaveSession(name, participants, currentSessionId ?? undefined);
     if (result) {
       currentSessionId = result.id;
-      currentSessionName = result.name;
       if (sessionNameInput) sessionNameInput.value = result.name;
       showSessionStatus('Сессия сохранена');
       renderSessionList();
@@ -589,7 +586,6 @@ const { tier = 'free', userId } = Astro.props;
 
   async function handleNewSession() {
     currentSessionId = null;
-    currentSessionName = '';
     if (sessionNameInput) sessionNameInput.value = '';
     clearAll();
     showSessionStatus('Новая сессия');
@@ -602,7 +598,6 @@ const { tier = 'free', userId } = Astro.props;
     if (ok) {
       if (currentSessionId === id) {
         currentSessionId = null;
-        currentSessionName = '';
         if (sessionNameInput) sessionNameInput.value = '';
       }
       renderSessionList();
diff --git a/src/components/dm/NotesPanel.astro b/src/components/dm/NotesPanel.astro
index 9f1379e..9e4bda6 100644
--- a/src/components/dm/NotesPanel.astro
+++ b/src/components/dm/NotesPanel.astro
@@ -49,7 +49,6 @@ const { tier = 'free', userId } = Astro.props;
     let debounceTimer: ReturnType<typeof setTimeout> | null = null;
     let hideIndicatorTimer: ReturnType<typeof setTimeout> | null = null;
     let dbNoteId: number | null = null;
-    let isLoading = false;
 
     function formatTime(date: Date): string {
       return date.toLocaleTimeString('ru-RU', { hour: '2-digit', minute: '2-digit' });
@@ -123,23 +122,19 @@ const { tier = 'free', userId } = Astro.props;
 
     async function loadSavedNotes() {
       if (isPro) {
-        isLoading = true;
         const note = await loadDbNotes();
         if (note) {
           dbNoteId = note.id;
           textarea.value = note.content ?? '';
         } else {
-          // Try to create a new note if none exists
           const newId = await createDbNote('');
           if (newId) {
             dbNoteId = newId;
             textarea.value = '';
           } else {
-            // Fallback to localStorage if DB is unavailable
             textarea.value = loadNotes();
           }
         }
-        isLoading = false;
       } else {
         const saved = loadNotes();
         textarea.value = saved;
diff --git a/src/components/dm/Open5eReference.astro b/src/components/dm/Open5eReference.astro
index 5522e66..a54fd8a 100644
--- a/src/components/dm/Open5eReference.astro
+++ b/src/components/dm/Open5eReference.astro
@@ -171,11 +171,7 @@ import DmButton from "./DmButton.astro";
 
 <script>
   import { Open5eUIManager } from "@/lib/client/open5e-ui";
-  import {
-    getCachedTranslation,
-    setCachedTranslation,
-    fetchTranslation,
-  } from "@/lib/client/translation";
+  import { fetchTranslation } from "@/lib/client/translation";
 
   const CR_OPTIONS = [
     { value: "", label: "Все ОП" },
@@ -544,12 +540,10 @@ import DmButton from "./DmButton.astro";
         btn.textContent = "Переведено";
         btn.disabled = true;
 
-        // Re-render detail with translation
         const state = manager.state;
         if (state.selectedItem && state.selectedItem.key === slug) {
-          const cached = getCachedTranslation(slug, type);
-          const isTranslated = cached !== null;
-          const item = mergeWithTranslation(state.selectedItem, cached);
+          const isTranslated = translated !== null;
+          const item = mergeWithTranslation(state.selectedItem, translated);
           detailContent.innerHTML = state.tab === "monsters"
             ? renderMonsterDetail(item as Monster, isTranslated)
             : renderSpellDetail(item as Spell, isTranslated);
diff --git a/src/lib/ai/kimi.ts b/src/lib/ai/kimi.ts
index 24b5bc9..c77029f 100644
--- a/src/lib/ai/kimi.ts
+++ b/src/lib/ai/kimi.ts
@@ -1,4 +1,3 @@
-import { z } from "zod";
 import {
   npcParamsSchema,
   npcResultSchema,
diff --git a/src/lib/ai/openrouter.ts b/src/lib/ai/openrouter.ts
index 5f5889a..dcdf17a 100644
--- a/src/lib/ai/openrouter.ts
+++ b/src/lib/ai/openrouter.ts
@@ -1,6 +1,4 @@
-import { z } from "zod";
 import { npcResultSchema, type NPCResult, type NPCParams, type Open5eMonster } from "@/lib/ai/types";
-import type { Monster } from "@/lib/open5e/client";
 
 const OPENROUTER_API_URL = "https://openrouter.ai/api/v1/chat/completions";
 const DEFAULT_MODEL = "llama-3.3-70b:free";
@@ -121,7 +119,7 @@ export async function translateOpen5eContent(
     return parsed as Record<string, unknown>;
   } catch (err) {
     if (err instanceof Error && err.name === "AbortError") {
-      throw new Error("OpenRouter request timed out after 10s");
+      throw new Error("OpenRouter request timed out after 10s", { cause: err });
     }
     throw err;
   } finally {
@@ -197,7 +195,7 @@ export async function generateNPC(
     return validated.data;
   } catch (err) {
     if (err instanceof Error && err.name === "AbortError") {
-      throw new Error("OpenRouter request timed out after 10s");
+      throw new Error("OpenRouter request timed out after 10s", { cause: err });
     }
     throw err;
   } finally {
diff --git a/src/pages/api/dm/ai/generate.ts b/src/pages/api/dm/ai/generate.ts
index 7919a70..4e8e3d0 100644
--- a/src/pages/api/dm/ai/generate.ts
+++ b/src/pages/api/dm/ai/generate.ts
@@ -142,6 +142,7 @@ export const POST: APIRoute = async ({ request, locals }) => {
   try {
     await incrementGenerationCounter(user.id, modelName);
   } catch {
+    // best-effort: counter increment failures should not block the response
   }
 
   const response: { npc: NPCResult & { id: number }; reference?: Open5eMonster } = {
diff --git a/src/pages/api/dm/ai/history.ts b/src/pages/api/dm/ai/history.ts
index 7717fc2..3d3932c 100644
--- a/src/pages/api/dm/ai/history.ts
+++ b/src/pages/api/dm/ai/history.ts
@@ -2,7 +2,7 @@ import type { APIRoute } from "astro";
 import { jsonResponse, handleCorsPreflight } from "@/lib/cors";
 import { db } from "@/db/client";
 import { npcs } from "@/db/schema";
-import { eq, desc, sql, count } from "drizzle-orm";
+import { eq, desc, count } from "drizzle-orm";
 
 export const prerender = false;
 
diff --git a/tests/ai-generate-api.test.ts b/tests/ai-generate-api.test.ts
index b6adc1f..d1ea38d 100644
--- a/tests/ai-generate-api.test.ts
+++ b/tests/ai-generate-api.test.ts
@@ -37,11 +37,15 @@ function mockRequest(
   } as unknown as Request;
 }
 
+// vi.mock factories are hoisted, so refs they read must use var (not let/const)
+// to be visible at hoist time without ReferenceError.
+/* eslint-disable no-var */
 var mockOpenRouterNPC = vi.fn();
 var mockKimiNPC = vi.fn();
 var mockSearchMonsters = vi.fn();
 var mockCheckRateLimit = vi.fn();
 var mockIncrementCounter = vi.fn();
+/* eslint-enable no-var */
 
 vi.mock("@/lib/ai/openrouter", () => ({
   generateNPC: (...args: unknown[]) => mockOpenRouterNPC(...args),
diff --git a/tests/history-api.test.ts b/tests/history-api.test.ts
index ebd2ed6..752c248 100644
--- a/tests/history-api.test.ts
+++ b/tests/history-api.test.ts
@@ -96,7 +96,7 @@ function createMockDb() {
   };
 }
 
-let mockDb = createMockDb();
+const mockDb = createMockDb();
 
 vi.mock("drizzle-orm", async (importOriginal) => {
   const actual = await importOriginal<typeof import("drizzle-orm")>();
diff --git a/tests/initiative-api.test.ts b/tests/initiative-api.test.ts
index efa2e64..1acc136 100644
--- a/tests/initiative-api.test.ts
+++ b/tests/initiative-api.test.ts
@@ -12,18 +12,6 @@ const mockUser = {
   createdAt: new Date("2024-01-01"),
 };
 
-const mockUser2 = {
-  id: 2,
-  vkId: null,
-  yandexId: null,
-  email: null,
-  name: "Other User",
-  avatar: null,
-  tier: "free" as const,
-  boostyVerifiedAt: null,
-  createdAt: new Date("2024-01-01"),
-};
-
 function mockRequest(
   url: string,
   origin: string,
@@ -132,7 +120,7 @@ function createMockDb() {
   };
 }
 
-let mockDb = createMockDb();
+const mockDb = createMockDb();
 
 vi.mock("drizzle-orm", async (importOriginal) => {
   const actual = await importOriginal<typeof import("drizzle-orm")>();
diff --git a/tests/notes-api.test.ts b/tests/notes-api.test.ts
index a197530..dea94b8 100644
--- a/tests/notes-api.test.ts
+++ b/tests/notes-api.test.ts
@@ -12,18 +12,6 @@ const mockUser = {
   createdAt: new Date("2024-01-01"),
 };
 
-const mockUser2 = {
-  id: 2,
-  vkId: null,
-  yandexId: null,
-  email: null,
-  name: "Other User",
-  avatar: null,
-  tier: "free" as const,
-  boostyVerifiedAt: null,
-  createdAt: new Date("2024-01-01"),
-};
-
 function mockRequest(
   url: string,
   origin: string,
@@ -132,7 +120,7 @@ function createMockDb() {
   };
 }
 
-let mockDb = createMockDb();
+const mockDb = createMockDb();
 
 vi.mock("drizzle-orm", async (importOriginal) => {
   const actual = await importOriginal<typeof import("drizzle-orm")>();
diff --git a/tests/open5e-types.test.ts b/tests/open5e-types.test.ts
index ad552bc..b320adc 100644
--- a/tests/open5e-types.test.ts
+++ b/tests/open5e-types.test.ts
@@ -5,6 +5,7 @@ import type { Monster, Spell } from "../src/lib/open5e/client";
 // If a listed key is missing from the interface, TypeScript will error at compile time.
 type AssertKeys<T, K extends keyof T> = K;
 
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 type _MonsterHasAllFields = AssertKeys<
   Monster,
   | "name"
@@ -34,6 +35,7 @@ type _MonsterHasAllFields = AssertKeys<
   | "condition_immunities"
 >;
 
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 type _SpellHasAllFields = AssertKeys<
   Spell,
   | "name"
diff --git a/tests/translate-api.test.ts b/tests/translate-api.test.ts
index 1a4fd02..0077343 100644
--- a/tests/translate-api.test.ts
+++ b/tests/translate-api.test.ts
@@ -77,7 +77,7 @@ function createMockDb() {
   };
 }
 
-let mockDb = createMockDb();
+const mockDb = createMockDb();
 
 vi.mock("drizzle-orm", async (importOriginal) => {
   const actual = await importOriginal<typeof import("drizzle-orm")>();
diff --git a/tests/translation-client.test.ts b/tests/translation-client.test.ts
index 587eb0d..56d79fc 100644
--- a/tests/translation-client.test.ts
+++ b/tests/translation-client.test.ts
@@ -3,7 +3,7 @@ import { describe, it, expect, vi, beforeEach } from "vitest";
 const mockPostMessage = vi.fn();
 const mockAddEventListener = vi.fn();
 
-function MockBroadcastChannel(this: unknown, _name: string) {
+function MockBroadcastChannel(this: unknown) {
   return {
     postMessage: mockPostMessage,
     addEventListener: mockAddEventListener,
@@ -75,7 +75,6 @@ describe("translation service", () => {
     global.fetch = mockFetch as unknown as typeof fetch;
 
     const {
-      getCachedTranslation,
       setCachedTranslation,
       fetchTranslation,
       clearTranslationCache,