Build all apps from Markdown content; Compose Desktop replaces GTK on Linux and Windows

- content/ + scripts/build-content.py produce content.json for every app
- stable lesson IDs with one-time progress migration (Swift, Kotlin)
- shared answer-check tests (tests/answers.json) for Kotlin and Swift
- android/desktop: Compose app with updater, speech and GTK progress import
- CI packages AppImage and Windows zip with ProGuard, runs the tests

Co-authored-by: Cursor <cursoragent@cursor.com>

content/anglictina/3-rocnik/01-jak-se-to-vyrabi.md

@@ -0,0 +1,82 @@
+---
+id: anglictina-3-jak-se-to-vyrabi
+puvodni: en.3.1
+nazev: Jak se to vyrábí
+popis: Trpný rod v přítomnosti a minulosti. Doplňování a kvíz.
+---
+
+# Výklad
+
+## Když je důležitější děj než původce
+*Passive*
+
+- English is spoken here. The window was broken last night.
+- Původce s by, jen když na něm záleží: The book was written by a nurse.
+- Modální trpný rod: The form must be signed. It can be recycled.
+- Nelze trpně vyjádřit každé sloveso. Happen trpný rod nemá.
+
+> Tip: be + příčestí. Čas nese sloveso be, ne příčestí.
+
+## Od suroviny k věci
+*Popis procesu*
+
+- The beans are picked by hand. They are dried in the sun.
+- The jars were labelled yesterday.
+- Waste paper is collected every Thursday.
+- A new bridge is being built. To už je průběhový trpný rod, zatím stačí ho poznat.
+
+> Tip: first, then, after that, finally. Původce často chybí, protože je obecný.
+
+
+# Doplňování
+
+## This bread ___ (bake) every morning.
+= is baked
+> Přítomný trpný rod.
+
+## The letters ___ (send) yesterday.
+= were sent
+> Minulý trpný rod, množné číslo.
+
+## The poem ___ (write) by a student.
+= was written
+> Write → written.
+
+## These bottles can ___ (recycle).
+= be recycled
+> Modální sloveso + be + příčestí.
+
+## The window ___ (not break) by the wind. Someone hit it.
+= wasn't broken|was not broken
+> Zápor minulého trpného rodu.
+
+
+# Kvíz
+
+## Which sentence is passive?
+- Someone stole my bike.
+- [x] My bike was stolen.
+- My bike stole.
+- Someone was steal my bike.
+> was + stolen.
+
+## The news ___ at ten.
+- is reading
+- are read
+- [x] is read
+- read
+> News je jednotné: is read.
+
+## You ___ wear a badge. The factory requires it, in the passive of must.
+- must be worn a badge
+- [x] A badge must be worn
+- A badge must worn
+- A badge is must wear
+> A badge must be worn.
+
+## They built the school in 1998. → The school ___ in 1998.
+- built
+- [x] was built
+- was build
+- has built
+> was built.