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>

desktop/src-tauri/tauri.conf.json

@@ -15,7 +15,7 @@
     "windows": [
       {
         "label": "main",
-        "title": "ThoughtSync",
+        "title": "Inkwell",
         "width": 1100,
         "height": 780,
         "minWidth": 480,