Fix four bugs and add logo/branding polish

- docker-compose: add register-user service (profiles: [tools]) with YAML anchor to avoid env duplication
- src/index.ts: show localhost instead of 0.0.0.0 in startup message
- file-view: render <img> inline for image/* MIME types
- file-list: add Copy link button per row (requires baseUrl param)
- layout: add hideLogo option; file view page hides the logo
- style.css: remove uppercase from .logo (Nanodrop not NANODROP), add button.copy-link styles, add .file-view img styles, widen last td

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/style.css

@@ -57,8 +57,7 @@ header {
 .logo {
   font-size: 13px;
   font-weight: 600;
-  letter-spacing: 0.08em;
-  text-transform: uppercase;
+  letter-spacing: 0.02em;
   text-decoration: none;
   color: var(--black);
 }
@@ -349,8 +348,26 @@ td a {
 }
 
 td:last-child {
-  width: 80px;
+  width: 160px;
   text-align: right;
+  white-space: nowrap;
+}
+
+/* ── Copy Link Button ───────────────────────────────────── */
+button.copy-link {
+  display: inline-block;
+  padding: 0.3rem 0.6rem;
+  font-family: var(--font);
+  font-size: 11px;
+  letter-spacing: 0.04em;
+  background: var(--white);
+  color: var(--black);
+  border: var(--border);
+  cursor: pointer;
+  margin-right: 0.4rem;
+}
+button.copy-link:hover {
+  background: var(--gray-100);
 }
 
 /* ── File View ──────────────────────────────────────────── */
@@ -376,6 +393,7 @@ td:last-child {
   margin-bottom: 0;
 }
 
+.file-view img,
 .file-view video,
 .file-view audio {
   width: 100%;