Free the Copy URL shortcut from ghost extension registrations (#6821)

* Rebind ghost Copy URL shortcut registrations to the pinned id

Chromium never hands a suggested shortcut to one extension while
another — even a long-gone one — still holds the registration. Profiles
that first loaded Copy URL before its id was pinned registered
Alt+Shift+L under an id derived from the extension's load path at the
time, so the pinned extension never receives the shortcut and the
keypress does nothing (#6816).

The quattro upgrade tried to repair this against one hardcoded
path-derived id, which only ever matched a single home directory. The
historical ids are unknowable in general — they hash long-gone absolute
paths through whatever symlinks existed then — but the registration
itself names the command, so a migration now rebinds any copy-url
command that points away from the pinned id, unless that id belongs to
an extension that is actually installed or the pinned extension already
holds a binding of its own.

Browsers rewrite Preferences on exit, which reverts any repair made
while one runs, so the migration asks for this user's browser windows to
be closed first — failing and staying pending when there is no terminal
to ask in or the prompt is declined. The backup a repair leaves behind
marks it as attempted but unverified: until a browser-free run confirms
the registration stayed repaired, the migration keeps itself pending
rather than trusting a disk state an open browser may still overwrite.

The upgrade-time repair is dropped: the upgrade already runs migrations,
so the migration is the single implementation.

Fixes #6816

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

* Pin the WhatsApp Slim extension id

Keyless unpacked extensions get path-derived ids, which go stale if the
load path or packaging ever changes — the same class of bug that broke
the Copy URL shortcut for pre-package installs. Pin the id with a
manifest key like the other bundled extensions.

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

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

default/chromium/extensions/whatsapp-slim/manifest.json

@@ -2,12 +2,19 @@
   "manifest_version": 3,
   "name": "WhatsApp Slim",
   "version": "1.1",
+  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAszLhFYxjvKqx1VAORt3M6b0H1Kz03cmQ1MrUjJZ8gj3nhRcvufk6PS17yUIjEdKKmuj+1HuFVwOaHJQsACGJXwn2TeKQqZmZx/83yd7ydgabHXTsJbhy5O+Yunv+VA1B2IX/phcXpkH9bPv2PuC/bQ13nmmAvT2b+EMyq8EPQHOoSWhE4M4kIhLDczTmxfJX5X3tTxH66952DYuQWvGpIXLAUXkvIgap0qemW68/LymPaWzcg6g3oE/nZ7C0j7JE5bnqLFxqXNlA9Jt+Ss/1Y33QL3OSD9EEsrpgueS0bbqtkmFQ9/jGlruIL+qj0xe+CAtqbJ5ty9H/sqi01kjfyQIDAQAB",
   "description": "Make WhatsApp Web follow the system theme and collapse its chat list in narrow windows, this extension is installed by Omarchy",
   "content_scripts": [
     {
-      "matches": ["https://web.whatsapp.com/*"],
-      "css": ["whatsapp.css"],
-      "js": ["system-theme.js"],
+      "matches": [
+        "https://web.whatsapp.com/*"
+      ],
+      "css": [
+        "whatsapp.css"
+      ],
+      "js": [
+        "system-theme.js"
+      ],
       "run_at": "document_start"
     }
   ]