feat: add logo SVGs, nav links, and UI polish

- Add logo-document.svg and logo-monogram.svg to static/img
- Show document logo in navbar alongside Diffdown wordmark
- Add Documents link to navbar (left of New Document) for logged-in users
- Remove Documents button from document view actions
- Add btn-danger style: red hover for outline delete button
- Fix list-view card hover highlight using background tint instead of border

static/css/style.css

···
     color: var(--primary);
 }
 .btn-outline:hover { background: var(--primary); color: #fff; }
+.btn-danger.btn-outline:hover { background: var(--danger); border-color: var(--danger); color: #fff; }
 .btn-link {
     background: none;
     border: none;
···
 
 .repo-list.list-view .repo-card h3 { margin-bottom: 0; font-size: 1rem; font-weight: 500; }
 .repo-list.list-view .repo-card time { margin-top: 0; margin-left: auto; }
+.repo-list.list-view .repo-card:hover { border-color: var(--border); background: color-mix(in srgb, var(--primary) 5%, var(--bg-card)); }
 
 .repo-card {
     display: block;

static/img/logo-document.svg

···
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   width="400"
+   height="511.24261"
+   viewBox="0 0 400 511.24261"
+   version="1.1"
+   xml:space="preserve"
+   style="clip-rule:evenodd;fill-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:2"
+   id="svg8"
+   sodipodi:docname="logo-document.svg"
+   inkscape:version="1.3.2 (091e20e, 2023-11-25)"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"><sodipodi:namedview
+   id="namedview1"
+   pagecolor="#ffffff"
+   bordercolor="#000000"
+   borderopacity="0.25"
+   inkscape:showpageshadow="2"
+   inkscape:pageopacity="0.0"
+   inkscape:pagecheckerboard="0"
+   inkscape:deskcolor="#d1d1d1"
+   inkscape:zoom="0.53777778"
+   inkscape:cx="431.40496"
+   inkscape:cy="530.88843"
+   inkscape:window-width="1776"
+   inkscape:window-height="1184"
+   inkscape:window-x="2789"
+   inkscape:window-y="31"
+   inkscape:window-maximized="0"
+   inkscape:current-layer="svg8" /><defs
+   id="defs8" />
+    
+    
+    
+    
+    
+    
+    
+    <g
+   id="g9"
+   transform="matrix(11.111111,0,0,11.61915,-22.222222,-23.2383)"><path
+     d="M 2,4 C 2,2.895 2.895,2 4,2 h 22 l 12,12 v 30 c 0,1.105 -0.895,2 -2,2 H 4 C 2.895,46 2,45.105 2,44 Z"
+     style="fill:#2563eb"
+     id="path1" /><g
+     transform="matrix(0,-1.475264,1,0,-17.976555,48.258067)"
+     id="g2">
+        <path
+   d="m 11,28 c 0,0.552 -0.304,1 -0.678,1 H 7.678 C 7.304,29 7,28.552 7,28 7,27.448 7.304,27 7.678,27 h 2.644 C 10.696,27 11,27.448 11,28 Z"
+   style="fill:#03d02c"
+   id="path2" />
+    </g><g
+     transform="matrix(1.495816,0,0,1,-3.470715,7)"
+     id="g3">
+        <path
+   d="m 11,28 c 0,0.552 -0.3,1 -0.669,1 H 7.669 C 7.3,29 7,28.552 7,28 7,27.448 7.3,27 7.669,27 h 2.662 C 10.7,27 11,27.448 11,28 Z"
+   style="fill:#03d02c"
+   id="path3" />
+    </g><path
+     d="M 26,2 38,14 H 28 c -1.105,0 -2,-0.895 -2,-2 z"
+     style="fill:#1a56db;fill-rule:nonzero"
+     id="path4" /><g
+     transform="matrix(1.226958,0,0,1,-1.581784,0)"
+     id="g5">
+        <path
+   d="m 29,21 c 0,0.552 -0.365,1 -0.815,1 H 7.815 C 7.365,22 7,21.552 7,21 7,20.448 7.365,20 7.815,20 h 20.37 C 28.635,20 29,20.448 29,21 Z"
+   style="fill:#ffffff;fill-opacity:0.4"
+   id="path5" />
+    </g><g
+     transform="matrix(1.51098,0,0,1,-3.576862,0)"
+     id="g6">
+        <path
+   d="m 11,28 c 0,0.552 -0.297,1 -0.662,1 H 7.662 C 7.297,29 7,28.552 7,28 7,27.448 7.297,27 7.662,27 h 2.676 C 10.703,27 11,27.448 11,28 Z"
+   style="fill:#fca5a5"
+   id="path6" />
+    </g><g
+     transform="translate(2)"
+     id="g7">
+        <path
+   d="m 27,28 c 0,0.552 -0.448,1 -1,1 H 14 c -0.552,0 -1,-0.448 -1,-1 0,-0.552 0.448,-1 1,-1 h 12 c 0.552,0 1,0.448 1,1 z"
+   style="fill:#ffffff;fill-opacity:0.3"
+   id="path7" />
+    </g><g
+     transform="matrix(1.055556,0,0,1,1.277778,0)"
+     id="g8">
+        <path
+   d="m 31,35 c 0,0.552 -0.425,1 -0.947,1 H 13.947 C 13.425,36 13,35.552 13,35 c 0,-0.552 0.425,-1 0.947,-1 H 30.053 C 30.575,34 31,34.448 31,35 Z"
+   style="fill:#ffffff;fill-opacity:0.8"
+   id="path8" />
+    </g></g>
+</svg>

static/img/logo-monogram.svg

···
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="210mm"
+   height="297mm"
+   viewBox="0 0 210 297"
+   version="1.1"
+   id="svg1"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg">
+  <defs
+     id="defs1" />
+  <g
+     id="layer1">
+    <g
+       id="g2">
+      <text
+         xml:space="preserve"
+         style="font-size:50.8px;line-height:1;font-family:'Inter 18pt';-inkscape-font-specification:'Inter 18pt';letter-spacing:0px;fill:#2563eb;fill-opacity:1;stroke-width:6.61432"
+         x="52.5"
+         y="141.88016"
+         id="text1"><tspan
+           id="tspan1"
+           style="font-size:50.8px;fill:#2563eb;fill-opacity:1;stroke-width:6.61432"
+           x="52.5"
+           y="141.88016">D</tspan></text>
+      <text
+         xml:space="preserve"
+         style="font-size:50.8px;line-height:1;font-family:'Inter 18pt';-inkscape-font-specification:'Inter 18pt';letter-spacing:0px;fill:#0000ff;stroke-width:6.61432"
+         x="78.900238"
+         y="141.22972"
+         id="text2"><tspan
+           id="tspan2"
+           style="stroke-width:6.61432"
+           x="78.900238"
+           y="141.22972">d</tspan></text>
+    </g>
+  </g>
+</svg>

templates/base.html

···
 </head>
 <body>
     <nav class="navbar">
-        <a href="/" class="logo">Diffdown</a>
+        <a href="/" class="logo">
+            <img src="/static/img/logo-document.svg" alt="" width="22" height="28" style="vertical-align:middle;margin-right:0.4rem">Diffdown
+        </a>
         <div class="nav-right">
             {{if .User}}
-                <a href="/docs/new">New Document</a>
+                <a href="/">Documents</a>
                 <span class="nav-user">{{.User.Name}}</span>
                 <form method="post" action="/auth/logout" style="display:inline">
                     <button type="submit" class="btn-link">Log out</button>

templates/document_view.html

···
         </div>
         <div class="file-actions">
             <a href="/docs/{{.Doc.RKey}}/edit" class="btn btn-sm">Edit</a>
-            <button class="btn btn-sm btn-outline" onclick="deleteDocument('{{.Doc.RKey}}')">Delete</button>
+            <button class="btn btn-sm btn-outline btn-danger" onclick="deleteDocument('{{.Doc.RKey}}')">Delete</button>
         </div>
     </div>
     <div class="markdown-body">