rename: the apps say Inkwell — web, desktop, Android and server strings

ThoughtSync is renamed Inkwell ("Fabled Inkwell" in full; Scribe note 5071).
This is step 1 of milestone 481: every string a person reads in the running
apps. Identities installed clients depend on are deliberately untouched — the
Tauri productName (it derives the .deb Package: field), identifier and binary
name, applicationId, X-ThoughtSync-* headers, the export's app marker, env vars,
module and crate names.

- web: title, PWA manifest (name "Fabled Inkwell", short_name "Inkwell"),
  offline page, icon labels, build labels, prompts, notification title
- server: site_name default, import error, link-preview User-Agent
- 0030: a stored site_name of exactly the old default follows the rename. The
  Settings page saves every key, so most servers hold "ThoughtSync" without an
  admin ever having chosen it; a name they typed is left alone
- desktop: window title, default device name, local-mode site name, log line
- android: app_name and the strings that name the app
- core: probe and compatibility messages

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/public/icon-maskable.svg

@@ -1,4 +1,4 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" role="img" aria-label="ThoughtSync">
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" role="img" aria-label="Inkwell">
   <!-- Maskable variant: full-bleed background so platform masks (circle, squircle,
        rounded-square) never clip the glyph. The graph sits inside the central 80%
        safe zone. Same mark as icon.svg. -->

frontend/public/icon.svg

@@ -1,4 +1,4 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" role="img" aria-label="ThoughtSync">
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" role="img" aria-label="Inkwell">
   <!-- Rounded-tile app icon: brand-yellow background + a small knowledge-graph
        constellation (a hub node linked to three thoughts) evoking linked notes. -->
   <rect width="512" height="512" rx="112" fill="#F5C518"/>

frontend/public/manifest.webmanifest

@@ -1,7 +1,7 @@
 {
   "id": "/",
-  "name": "ThoughtSync",
-  "short_name": "ThoughtSync",
+  "name": "Fabled Inkwell",
+  "short_name": "Inkwell",
   "description": "Capture a fleeting thought in a second — a self-hosted Keep-style board that grows into a lightweight second brain.",
   "start_url": "/",
   "scope": "/",

frontend/public/offline.html

@@ -4,7 +4,7 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <meta name="theme-color" content="#F5C518" />
-    <title>Offline · ThoughtSync</title>
+    <title>Offline · Inkwell</title>
     <style>
       :root {
         color-scheme: light dark;
@@ -107,7 +107,7 @@
         </g>
       </svg>
       <h1>You're offline</h1>
-      <p>ThoughtSync needs a connection to your server to load. Reconnect and try again.</p>
+      <p>Inkwell needs a connection to your server to load. Reconnect and try again.</p>
       <button type="button" onclick="location.reload()">Retry</button>
     </main>
   </body>

frontend/public/sw.js

@@ -1,4 +1,4 @@
-// ThoughtSync service worker — installable shell, deliberately NOT offline-first.
+// Inkwell service worker — installable shell, deliberately NOT offline-first.
 //
 // This exists so the web app satisfies the PWA install criteria ("Add to Home
 // Screen") and shows a friendly page when a navigation happens with no network.