v0.1.2: rebrand to Naiv-QR, target AMO-listed distribution

Pre-AMO rename. The extension is now "Naiv-QR" everywhere it surfaces
to users (toolbar tooltip, popup title, icon aria-label, README,
package.json). Distribution target is AMO-listed, so the manifest no
longer declares gecko.update_url — Firefox handles auto-updates from
AMO directly for listed extensions, and the field is in fact rejected
by Mozilla's validator outside self-distribution mode.

- manifest.json: name → "Naiv-QR"; gecko.id → naiv-qr@addons.naiv.no;
  remove update_url.
- package.json: name → "naiv-qr"; drop --self-hosted from lint script
  now that we're back to Mozilla-hosted validation.
- popup/popup.html: <title> updated.
- icons/icon.svg: aria-label updated.
- README: retitled, removed Self-distribution section, updated
  Publishing-to-AMO section to spell out the listed-distribution flow.

Build artifact is now web-ext-artifacts/naiv-qr-<ver>.zip (web-ext
derives the filename from manifest.name).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -1,4 +1,4 @@
-# Share as QR
+# Naiv-QR
 
 A small Firefox extension that turns the current tab's URL into a scannable QR
 code, so you can hand a page off to a phone (or another machine) without
@@ -95,8 +95,13 @@ Permissions used (both are the minimum the feature needs):
 
 ## Publishing to AMO
 
-`bun run package` produces a deterministic `web-ext-artifacts/share_as_qr-<ver>.zip`
-from a clean checkout. The zip contains only the files in `dist/`:
+The plan is to distribute Naiv-QR through
+[addons.mozilla.org](https://addons.mozilla.org) as a **listed** extension.
+With listed distribution Firefox handles auto-updates from AMO directly —
+the manifest must therefore **not** declare `gecko.update_url`.
+
+`bun run package` produces `web-ext-artifacts/naiv_qr-<ver>.zip` from a
+clean checkout. The zip contains only the files in `dist/`:
 
 ```
 dist/
@@ -108,8 +113,15 @@ dist/
   popup/popup.js         (bundled, minified)
 ```
 
-For AMO source-code review, point the reviewer at this repository and the
-pinned upstream commit of `vendor/qrcode.js` documented below.
+For first-time AMO submission, use the web UI at
+https://addons.mozilla.org/developers/addon/submit/ — upload the zip, then
+fill in summary, description, screenshots, categories, and license (MIT).
+Subsequent versions can be uploaded via the API with `web-ext sign
+--channel listed` once you have AMO credentials.
+
+For the AMO source-code review step (required because of the `bun build`
+step), point the reviewer at this repository and the pinned upstream commit
+of `vendor/qrcode.js` documented below.
 
 ## Third-party code