Rebrand to mtgc: pirate-ship logo, lowercase app name, mtgc binary

- New logomark: an original pirate-ship silhouette (hull, twin billowing
  sails, swallow-tail pennant) in the terracotta brand gradient on a dark
  square — a nod to the MTG card "Pirate Ship", not a reproduction of its
  art. Source at src-tauri/icons/logo-source.svg; regenerate the full
  platform icon set (desktop/Windows Store/iOS/Android) with
  `cargo tauri icon src-tauri/icons/logo-source.svg`.
- Apply it in-app via a new inline ShipLogo component (App.tsx), replacing
  the old "M" sidebar mark and "✦" empty-state mark with dark rounded
  squares containing the ship glyph.
- Rename the app to lowercase "mtgc" everywhere: window title and
  productName (tauri.conf.json), <title> (index.html), sidebar brand text,
  empty-state heading.
- Rename the Tauri package/binary mtgc-app -> mtgc (and its lib crate
  mtgc_app_lib -> mtgc_lib), so `cargo tauri build` now produces
  target/release/mtgc; updated main.rs and every README reference.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src-tauri/Cargo.toml

@@ -1,13 +1,13 @@
 [package]
-name = "mtgc-app"
+name = "mtgc"
 version = "0.1.0"
 edition = "2021"
-description = "MTG Library Catalog desktop app"
+description = "mtgc — personal Magic: The Gathering library catalog"
 
 [lib]
 # The Tauri app logic lives in a lib so the same entry point can serve desktop
 # and (later) mobile targets.
-name = "mtgc_app_lib"
+name = "mtgc_lib"
 crate-type = ["staticlib", "cdylib", "rlib"]
 
 [build-dependencies]

src-tauri/icons/logo-source.svg

@@ -0,0 +1,35 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200">
+  <defs>
+    <linearGradient id="bg" x1="0" y1="0" x2="1" y2="1">
+      <stop offset="0" stop-color="#22242b"/>
+      <stop offset="1" stop-color="#15161a"/>
+    </linearGradient>
+    <linearGradient id="ship" x1="0" y1="0" x2="0" y2="1">
+      <stop offset="0" stop-color="#d86e56"/>
+      <stop offset="1" stop-color="#a8412d"/>
+    </linearGradient>
+  </defs>
+
+  <rect x="0" y="0" width="200" height="200" fill="url(#bg)"/>
+
+  <!-- waterline waves -->
+  <path d="M8,161 Q26,153 44,161 T80,161 T116,161 T152,161 T188,161" fill="none" stroke="#3a8fd0" stroke-width="5" stroke-linecap="round" opacity="0.55"/>
+  <path d="M2,175 Q21,166 40,175 T78,175 T116,175 T154,175 T192,175" fill="none" stroke="#3a8fd0" stroke-width="5" stroke-linecap="round" opacity="0.3"/>
+
+  <!-- hull -->
+  <path d="M21,137 L179,137 L159,176 Q100,193 41,176 Z" fill="url(#ship)"/>
+  <!-- deck rail highlight -->
+  <rect x="21" y="133" width="158" height="6" rx="3" fill="url(#ship)"/>
+
+  <!-- mast -->
+  <rect x="95" y="7" width="10" height="127" fill="url(#ship)"/>
+
+  <!-- foresail (smaller, forward) -->
+  <path d="M100,32 C73,40 56,65 59,94 C60,103 71,110 87,113 L100,113 Z" fill="url(#ship)"/>
+
+  <!-- main sail (billowing aft) -->
+  <path d="M100,14 C147,26 168,73 160,114 C158,127 140,137 119,140 L100,140 Z" fill="url(#ship)"/>
+
+  <!-- pirate pennant -->
+  <path d="M100,7 L126,13 L109,18 L126,23 L100,30 Z" fill="url(#ship)"/>
+</svg>

src-tauri/src/main.rs

@@ -2,5 +2,5 @@
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
 fn main() {
-    mtgc_app_lib::run()
+    mtgc_lib::run()
 }

src-tauri/tauri.conf.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
-  "productName": "MTG Library",
+  "productName": "mtgc",
   "version": "0.1.0",
   "identifier": "com.garrettmills.mtgc",
   "build": {
@@ -13,7 +13,7 @@
     "windows": [
       {
         "label": "main",
-        "title": "MTG Library",
+        "title": "mtgc",
         "width": 1200,
         "height": 800,
         "resizable": true