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/tables/README.md

@@ -0,0 +1,13 @@
+# Campaign tables
+
+Tables placed here belong to this campaign and override the game's tables when
+names collide. The lookup order for `journal roll <name>` is:
+
+1. `campaigns/<name>/tables/<name>.csv`
+2. `games/<game>/tables/<name>.csv`
+
+Use this directory for tables specific to this campaign's setting or cast. The
+game's own tables do not need to be copied here.
+
+Format: a CSV with a `min,max,text` header and an optional `tags` column. See
+`docs/oracle.md`.