chore(knip): add config and remove dead code/deps

- knip.json: scope to src, ignore submodule/worktrees, mark
  generated abi.ts as unresolved-allowed, honor @public JSDoc tag
- drop 14 orphaned files (12 ui components, model/Bank, model/Pix)
- drop 18 unused deps (urql, tanstack, wagmi/{core,vue}, graphql,
  permissionless, graphql-codegen suite, axe-core, lighthouse,
  vue/test-utils)
- drop 4 unused exports and de-export 9 internal-only types
- mark NetworksTestnet as @public (in-flight testnet support)

src/model/Faq.ts

@@ -1,11 +1,11 @@
 export type Faq = Section[];
 
-export type Section = {
+type Section = {
   name: string;
   items: Question[];
 };
 
-export type Question = {
+type Question = {
   title: string;
   content: string;
   isOpen?: boolean;