```

chore: refactor logging module, update genesis timestamp, remove model relationships, and reorganize routers

- Rename logging.py to logger.py and update import paths in poa.py and main.py
- Update devnet genesis timestamp to 1766828620
- Remove SQLModel Relationship declarations from Block, Transaction, and Receipt models
- Add SessionDep type alias and get_session dependency in coordinator-api deps
- Reorganize coordinator-api routers: replace explorer/registry with exchange, users, marketplace

apps/explorer-web/src/components/siteHeader.ts

@@ -1,18 +1,19 @@
 export function siteHeader(title: string): string {
+  const basePath = window.location.pathname.startsWith('/explorer') ? '/explorer' : '';
+  
   return `
     <header class="site-header">
       <div class="site-header__inner">
-        <a class="site-header__brand" href="/">AITBC Explorer</a>
-        <h1 class="site-header__title">${title}</h1>
+        <a class="site-header__brand" href="${basePath}/">AITBC Explorer</a>
         <div class="site-header__controls">
           <div data-role="data-mode-toggle"></div>
         </div>
         <nav class="site-header__nav">
-          <a href="/">Overview</a>
-          <a href="/blocks">Blocks</a>
-          <a href="/transactions">Transactions</a>
-          <a href="/addresses">Addresses</a>
-          <a href="/receipts">Receipts</a>
+          <a href="${basePath}/">Overview</a>
+          <a href="${basePath}/blocks">Blocks</a>
+          <a href="${basePath}/transactions">Transactions</a>
+          <a href="${basePath}/addresses">Addresses</a>
+          <a href="${basePath}/receipts">Receipts</a>
         </nav>
       </div>
     </header>