feat: add CI pipeline with ESLint, refactor deploy with rollback + Telegram

- Add eslint.config.mjs (flat config, eslint-config-next@16 + TypeScript)
- Add .gitea/workflows/ci.yaml (lint, test:unit, build on all branches)
- Refactor deploy.yaml: needs: [ci] gate, Docker rollback tag, Telegram notifications
- Fix 3 pre-existing lint errors (empty interfaces, ts-ignore, require imports)

memento-note/eslint.config.mjs

@@ -0,0 +1,64 @@
+import { defineConfig, globalIgnores } from "eslint/config";
+import nextVitals from "eslint-config-next/core-web-vitals";
+import nextTs from "eslint-config-next/typescript";
+
+const reactCompilerRules = [
+  "react-hooks/hooks",
+  "react-hooks/capitalized-calls",
+  "react-hooks/static-components",
+  "react-hooks/use-memo",
+  "react-hooks/void-use-memo",
+  "react-hooks/preserve-manual-memoization",
+  "react-hooks/memo-dependencies",
+  "react-hooks/incompatible-library",
+  "react-hooks/immutability",
+  "react-hooks/globals",
+  "react-hooks/refs",
+  "react-hooks/memoized-effect-dependencies",
+  "react-hooks/exhaustive-effect-dependencies",
+  "react-hooks/set-state-in-effect",
+  "react-hooks/no-deriving-state-in-effects",
+  "react-hooks/error-boundaries",
+  "react-hooks/purity",
+  "react-hooks/set-state-in-render",
+  "react-hooks/invariant",
+  "react-hooks/todo",
+  "react-hooks/syntax",
+  "react-hooks/unsupported-syntax",
+  "react-hooks/config",
+  "react-hooks/gating",
+  "react-hooks/rule-suppression",
+  "react-hooks/fbt",
+  "react-hooks/component-hook-factories",
+];
+
+const disabledCompilerRules = Object.fromEntries(
+  reactCompilerRules.map((r) => [r, "off"])
+);
+
+const eslintConfig = defineConfig([
+  ...nextVitals,
+  ...nextTs,
+  globalIgnores([
+    ".next/**",
+    "out/**",
+    "build/**",
+    "next-env.d.ts",
+    "scripts/**",
+    "prisma/**",
+    "socket-server.ts",
+    "tests/**",
+  ]),
+  {
+    rules: {
+      ...disabledCompilerRules,
+      "react-hooks/exhaustive-deps": "warn",
+      "react-hooks/rules-of-hooks": "error",
+      "@typescript-eslint/no-unused-vars": ["warn", { argsIgnorePattern: "^_" }],
+      "@typescript-eslint/no-explicit-any": "warn",
+      "react/no-unescaped-entities": "off",
+    },
+  },
+]);
+
+export default eslintConfig;