feat: add the-ballad-of-chalk campaign

Cloud Empress campaign for 弗莱格, a sellsword obsessed with chalk.
Ships the brief, PC sheet, state files, a starting location, and the
session 0001 log. The opening hook and hidden truth live in gm/.

campaigns/the-ballad-of-chalk/state/threads.md

@@ -0,0 +1,9 @@
+# Threads
+
+Open questions and unresolved goals. Status is one of: open, resolved, abandoned.
+
+| Thread | Status | Notes |
+|--------|--------|-------|
+| 精通白垩，向父母证明自己 | open | 弗莱格的执念；心灵 18 是他最大的障碍。 |
+| 那个泥巴孩子是不是唯一幸存者 | open | 她自称村庄唯一的幸存者。 |
+| 白垩从何而来、父母身在何处 | open | 出身与执念的源头，尚未打捞。 |