refactor: restructure project from bookmann to shelf

- Rename project from 'bookmann' to 'shelf'
- Move all backend/ contents to root level (flatten structure)
- Update Go module name from 'bookmann' to 'shelf'
- Update all import paths to use new 'shelf' module
- Update Dockerfile to work without backend/ subdirectory
- Update docker-compose.yml to use new structure and rename containers
- Update .gitignore for new file paths
- Update README.md with new project name and structure
- Regenerate database code with new module imports

templates/login.html

@@ -0,0 +1,65 @@
+{{template "base.html" .}}
+
+{{define "title"}}Login{{end}}
+
+{{define "content"}}
+<div class="container mx-auto px-4 py-8 max-w-md">
+    <div class="flex justify-between items-center mb-8">
+        <h1 class="text-3xl font-bold">Login</h1>
+        <select id="theme-select" class="px-3 py-2 border rounded" style="background-color: var(--bg-secondary); color: var(--text-primary); border-color: var(--border)" onchange="changeTheme()">
+            <option value="tokyo-night">Tokyo Night</option>
+            <option value="dracula">Dracula</option>
+            <option value="nord">Nord</option>
+            <option value="solarized-dark">Solarized Dark</option>
+            <option value="monokai">Monokai</option>
+            <option value="one-dark-pro">One Dark Pro</option>
+            <option value="material-dark">Material Dark</option>
+            <option value="catppuccin-mocha">Catppuccin Mocha</option>
+            <option value="catppuccin-macchiato">Catppuccin Macchiato</option>
+            <option value="catppuccin-frappe">Catppuccin Frappé</option>
+            <option value="catppuccin-latte">Catppuccin Latte</option>
+        </select>
+    </div>
+    
+    <form hx-post="/api/auth/login" hx-target="#result" hx-swap="innerHTML" class="card p-6 rounded-lg shadow-md border">
+        <div class="mb-4">
+            <label class="block mb-2" style="color: var(--text-secondary)">Email or Username</label>
+            <input type="text" name="login" class="w-full px-3 py-2 border rounded" style="background-color: var(--bg-primary); color: var(--text-primary); border-color: var(--border)" required>
+        </div>
+        <div class="mb-4">
+            <label class="block mb-2" style="color: var(--text-secondary)">Password</label>
+            <input type="password" name="password" class="w-full px-3 py-2 border rounded" style="background-color: var(--bg-primary); color: var(--text-primary); border-color: var(--border)" required>
+        </div>
+        <button type="submit" class="btn-primary w-full py-2 rounded">
+            Login
+        </button>
+    </form>
+    
+    <div id="result" class="mt-4 text-center"></div>
+    
+    <p class="text-center mt-4">
+        <a href="/register" class="text-blue-500 hover:underline">Don't have an account? Register</a>
+    </p>
+</div>
+<script>
+    function changeTheme() {
+        const theme = document.getElementById('theme-select').value;
+        applyTheme(theme);
+        const token = localStorage.getItem('token');
+        if (token) {
+            fetch('/api/auth/theme', {
+                method: 'PUT',
+                headers: {
+                    'Content-Type': 'application/json',
+                    'Authorization': 'Bearer ' + token
+                },
+                body: JSON.stringify({ theme })
+            }).catch(err => console.log('Theme save failed', err));
+        }
+    }
+    document.addEventListener('DOMContentLoaded', () => {
+        loadTheme();
+        document.getElementById('theme-select').value = localStorage.getItem('theme') || 'tokyo-night';
+    });
+</script>
+{{end}}