chore: eliminate all ESLint warnings, enforce --max-warnings 0 (#5)

Behavior-preserving lint cleanup of the 30 pre-existing warnings, fixed
by category (no blanket suppression):
- no-explicit-any (19): precise local types / ApiPromise for Substrate
  dynamic queries + 'as unknown as' casts (same pattern as TokensCard).
- no-console (4): dev-gated (import.meta.env.DEV) / warn; main.tsx prod
  console-suppression kept with a scoped documented disable.
- no-non-null-assertion (4): replaced '!' with explicit guards reusing
  the existing fallback/return paths.
- react-hooks/exhaustive-deps (3): missing dep is 't' (i18n) — adding it
  would re-fire blockchain fetches on language change; kept deps with a
  documented intentional disable.

Tighten the lint gate from --max-warnings 30 to 0 so no new warnings can
land. Verified: tsc 0 errors, eslint --max-warnings 0 clean, vite build ok.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pezkuwi-telegram-miniapp",
-  "version": "1.0.233",
+  "version": "1.0.235",
   "type": "module",
   "description": "Pezkuwichain Telegram Mini App - Forum, Announcements, Rewards",
   "author": "Pezkuwichain Team",
@@ -13,7 +13,7 @@
     "build:patch": "node scripts/bump-version.mjs patch && tsc && vite build",
     "build:no-bump": "tsc && vite build",
     "preview": "vite preview",
-    "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 30",
+    "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 0",
     "lint:fix": "eslint . --ext ts,tsx --fix",
     "format": "prettier --write \"src/**/*.{ts,tsx,css}\"",
     "typecheck": "tsc --noEmit",