feat(security,ui): self-host React deps, Tailwind, fonts; strict CSP; local QR; better selection state

Replace CDN React/ReactDOM/Babel with local libs; remove Babel and inline scripts
Build Tailwind locally, add safelist; switch to assets/tailwind.css
Self-host Font Awesome and Inter (CSS + woff2); remove external font CDNs
Implement strict CSP (no unsafe-inline/eval; scripts/styles/fonts from self)
Extract inline handlers; move PWA scripts to external files
Add local QR code generation (qrcode lib) and remove api.qrserver.com
Improve SessionTypeSelector visual selection (highlighted background and ring)
Keep PWA working with service worker and offline assets
Refs: CSP hardening, offline-first, no external dependencies

node_modules/yargs/build/lib/levenshtein.js

@@ -0,0 +1,58 @@
+"use strict";
+/*
+Copyright (c) 2011 Andrei Mackenzie
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.levenshtein = void 0;
+// levenshtein distance algorithm, pulled from Andrei Mackenzie's MIT licensed.
+// gist, which can be found here: https://gist.github.com/andrei-m/982927
+// Compute the edit distance between the two given strings
+function levenshtein(a, b) {
+    if (a.length === 0)
+        return b.length;
+    if (b.length === 0)
+        return a.length;
+    const matrix = [];
+    // increment along the first column of each row
+    let i;
+    for (i = 0; i <= b.length; i++) {
+        matrix[i] = [i];
+    }
+    // increment each column in the first row
+    let j;
+    for (j = 0; j <= a.length; j++) {
+        matrix[0][j] = j;
+    }
+    // Fill in the rest of the matrix
+    for (i = 1; i <= b.length; i++) {
+        for (j = 1; j <= a.length; j++) {
+            if (b.charAt(i - 1) === a.charAt(j - 1)) {
+                matrix[i][j] = matrix[i - 1][j - 1];
+            }
+            else {
+                matrix[i][j] = Math.min(matrix[i - 1][j - 1] + 1, // substitution
+                Math.min(matrix[i][j - 1] + 1, // insertion
+                matrix[i - 1][j] + 1)); // deletion
+            }
+        }
+    }
+    return matrix[b.length][a.length];
+}
+exports.levenshtein = levenshtein;