add angular-round selector

README.md

@@ -16,9 +16,10 @@ Temporary add-ons remain installed until Firefox restarts. For permanent local u
 
 1. Open a normal web page.
 2. Select the Glagolify toolbar icon.
-3. Press **Enable Glagolitic**. Press **Restore Cyrillic** to undo it.
+3. Choose **Round** or **Angular** letter shapes.
+4. Press **Enable Glagolitic**. Press **Restore Cyrillic** to undo it.
 
-The popup intentionally has one action. The background script owns one absolute enabled/disabled state per tab, broadcasts it to every frame, and supplies it to frames created or navigated later. State lasts across navigation and is discarded when the tab closes. Firefox internal pages (`about:`, browser UI), extension pages, and other protected pages cannot be modified; the popup reports that restriction.
+The popup keeps one action button and a two-choice letter-style selector. The selected style is stored as a global extension preference and updates every enabled tab immediately. The background script separately owns one absolute enabled/disabled state per tab, broadcasts it to every frame, and supplies both state and style to frames created or navigated later. Tab state lasts across navigation and is discarded when the tab closes. Firefox internal pages (`about:`, browser UI), extension pages, and other protected pages cannot be modified; the popup reports that restriction.
 
 Glagolify updates existing text and watches for text nodes that are inserted or changed later. It leaves `script`, `style`, `noscript`, `template`, `textarea`, `select`, `option`, effective `contenteditable` regions, and documents in `designMode` untouched. Visible form labels, validation messages, and button text are converted, while text controls and selectable options are not. Textual DOM hidden by HTML, CSS, or `aria-hidden` is converted proactively so it is already Glagolitic if revealed. The implementation only changes text-node data and a reversible inline font fallback; it does not replace or wrap page elements. Disconnected nodes are restored and released after each mutation batch, while nodes moved and reconnected in the same batch keep their state.
 
@@ -28,17 +29,22 @@ Open shadow roots present when Glagolify is enabled are handled, including neste
 
 The converter has an explicit, case-preserving mapping for all 33 letters of the modern Russian alphabet (66 uppercase/lowercase entries). Punctuation, whitespace, digits, Latin text, Cyrillic characters outside that mapping, and already-Glagolitic text remain unchanged. Letters shared by Russian and another Cyrillic alphabet are converted because their code points are the same.
 
-The mapping uses dedicated Glagolitic letters for `Ё` (Yo), `Й` (I), `Щ` (Shta), `Ю` (Yu), and `Я` (Small Yus). Modern Russian letters without exact historical one-to-one equivalents use these practical conventions:
+The mapping uses dedicated Glagolitic letters for `Ё` (Yo), `Й` (I), `Щ` (Shta), and `Ю` (Yu). Modern Russian letters without exact historical one-to-one equivalents use these conventions:
 
-- `Ь` → Yati (`Ⱑ` / `ⱑ`)
-- `Ы` → Yeri (`Ⱐ` / `ⱐ`)
-- `Э` → Yestu, the same output as `Е` (`Ⰵ` / `ⰵ`)
+- `Ь` → Yeri (`Ⱐ` / `ⱐ`)
+- `Ъ` → Yeru (`Ⱏ` / `ⱏ`)
+- `Ы` → the Yeru + Izhe digraph (`ⰟⰉ` / `ⱏⰹ`)
+- `Е` and `Э` → Yestu (`Ⰵ` / `ⰵ`)
+- `Я` → Yati (`Ⱑ` / `ⱑ`)
 
-## Bundled font
+## Bundled fonts
 
-`fonts/NotoSansGlagolitic-Regular.ttf` is bundled so converted characters remain legible when the operating system has no Glagolitic font. It is inserted before each affected element's existing computed font family, so non-Glagolitic characters continue to use the page's own typography. If the page genuinely changes an affected element's inline `font-family` while Glagolify is enabled, the extension retains that latest page-owned declaration, reapplies its Glagolitic fallback, and restores the latest page value when switched off.
+Glagolify bundles two OFL-licensed fonts so converted characters remain legible and the popup can switch between historical letter shapes:
 
-The font is **Noto Sans Glagolitic Regular**, sourced from the [Google Fonts repository](https://github.com/google/fonts/tree/main/ofl/notosansglagolitic) and distributed under the SIL Open Font License 1.1. The included license is at `fonts/OFL.txt`.
+- **Round:** [Noto Sans Glagolitic Regular](https://github.com/google/fonts/tree/main/ofl/notosansglagolitic), the standard rounded Unicode Glagolitic design. Its license is `fonts/OFL.txt`.
+- **Angular:** [Shafarik Regular](https://github.com/google/fonts/tree/main/ofl/shafarik) with OpenType Stylistic Set 3 (`ss03`), which Shafarik defines as Croatian Angular or Square Glagolitic. Its license is `fonts/Shafarik-OFL.txt`.
+
+The selected font is inserted before each affected element's existing computed font family, so non-Glagolitic characters continue to use the page's own typography. If the page genuinely changes an affected element's inline `font-family` while Glagolify is enabled, the extension retains that latest page-owned declaration, reapplies the selected Glagolitic fallback, and restores the latest page value when switched off.
 
 ## Automated checks
 
@@ -48,4 +54,4 @@ No install or build step is required. With Node.js available, run:
 npm test
 ```
 
-The test suite validates the complete 66-entry mapping, mixed-content preservation, case, already-Glagolitic behavior, and authoritative per-tab/background frame inheritance using Node's built-in test runner.
+The test suite validates the complete 66-entry mapping, mixed-content preservation, case, already-Glagolitic behavior, authoritative per-tab/background frame inheritance, and persisted round/angular font selection using Node's built-in test runner.