feat: tsuki Firefox theme for Nova (157+)

Adaptive light/dark static theme generated from @tsuki/tokens, plus an
optional userChrome.css layer (IBM Plex, tsuki radii, shu accent) that
overrides Nova's design tokens. Self-hosted via AMO unlisted signing and
Gitea releases.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "outDir": "dist",
+    "rootDir": "src",
+    "types": ["node"]
+  },
+  "include": ["src/**/*"]
+}