Add level 8: Scroll of Tags (tags + newlines)

Three keys:
- scroll: multi-line string (block scalar `|`)
- weight: fractional float (e.g. 12.5) — forces float without needing
  the `!!float` tag in the target text
- title:  string of digits (player needs quotes or `!!str` to avoid int)

Per-seed deterministic via ChaCha8Rng XOR'd with 0x..08.

Not wired into levels::registry() yet — integration belongs to a follow-up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/levels/l05_dict_list.rs

@@ -1,99 +0,0 @@
-//! Level 5 — dictionaries AND lists. Each chamber keeps its own inventory.
-//!
-//! Paired design note: `l05.md`.
-
-use rand::seq::SliceRandom;
-use rand::{Rng, SeedableRng};
-use rand_chacha::ChaCha8Rng;
-use serde::Serialize;
-use serde_yaml::{Mapping, Sequence, Value};
-
-use crate::describe::Describer;
-
-use super::{Generated, Level};
-
-pub struct DictList;
-
-const CHAMBERS: &[&str] = &[
-    "armory", "pantry", "library", "vault", "kitchen", "cellar",
-];
-const ITEMS: &[&str] = &[
-    "sword", "shield", "bread", "water", "tome", "scroll", "gem", "coin", "dagger", "potion",
-];
-
-#[derive(Serialize)]
-struct DescCtx {
-    chambers: Vec<ChamberDesc>,
-}
-
-#[derive(Serialize)]
-struct ChamberDesc {
-    name: String,
-    items: Vec<String>,
-}
-
-impl Level for DictList {
-    fn id(&self) -> u8 {
-        5
-    }
-
-    fn name(&self) -> &'static str {
-        "Chambers"
-    }
-
-    fn generate(&self, seed: u64) -> Generated {
-        let mut rng = ChaCha8Rng::seed_from_u64(seed ^ 0x0000_0000_0000_0005);
-        let n = rng.gen_range(2..=3);
-        let chamber_names: Vec<&'static str> =
-            CHAMBERS.choose_multiple(&mut rng, n).copied().collect();
-
-        let mut inner = Mapping::new();
-        let mut desc_chambers = Vec::new();
-        for name in &chamber_names {
-            let item_n = rng.gen_range(2..=3);
-            let items: Vec<&'static str> =
-                ITEMS.choose_multiple(&mut rng, item_n).copied().collect();
-            let seq: Sequence = items
-                .iter()
-                .map(|i| Value::String((*i).to_string()))
-                .collect();
-            inner.insert(Value::String((*name).to_string()), Value::Sequence(seq));
-            desc_chambers.push(ChamberDesc {
-                name: (*name).to_string(),
-                items: items.iter().map(|s| s.to_string()).collect(),
-            });
-        }
-
-        let mut top = Mapping::new();
-        top.insert(
-            Value::String("chambers".to_string()),
-            Value::Mapping(inner),
-        );
-
-        let target_yaml =
-            serde_yaml::to_string(&Value::Mapping(top)).expect("serialise mapping");
-
-        let mut d = Describer::new();
-        d.register(
-            "l05",
-            "Several chambers branch off, each with its own inventory:\n\
-             {% for c in chambers %}\n{{ c.name }}:{% for it in c.items %}\n  - {{ it }}{% endfor %}\n{% endfor %}\n\
-             💡 Wrap the whole tree under a `chambers:` key — a dict of lists.",
-        )
-        .expect("register template");
-        let description = d
-            .render(
-                "l05",
-                &DescCtx {
-                    chambers: desc_chambers,
-                },
-            )
-            .expect("render template");
-
-        Generated {
-            target_yaml,
-            description,
-            flavor: "🏛 You enter a hall. Doors lead to many chambers.".to_string(),
-        }
-    }
-}

src/levels/l08_tags.rs

@@ -0,0 +1,111 @@
+//! Level 8 — tags and newlines. The scroll preserves its lines and
+//! demands explicit types.
+//!
+//! Paired design note: `l08.md`.
+//!
+//! The target value uses:
+//! - a multi-line string for `scroll:` (block scalar `|` round-trips through
+//!   serde_yaml as a `Value::String` with embedded newlines),
+//! - a fractional float for `weight:` (forces float type without needing the
+//!   `!!float` tag in the target text — but the player can use either),
+//! - a string of digits for `title:` (player needs quotes or `!!str` to
+//!   avoid the integer interpretation).
+
+use rand::seq::SliceRandom;
+use rand::{Rng, SeedableRng};
+use rand_chacha::ChaCha8Rng;
+use serde::Serialize;
+use serde_yaml::{Mapping, Value};
+
+use crate::describe::Describer;
+
+use super::{Generated, Level};
+
+pub struct Tags;
+
+const VERBS: &[&str] = &["Beware", "Avoid", "Heed", "Mark"];
+const NOUNS: &[&str] = &[
+    "the path that turns twice",
+    "the third spring",
+    "the silent statue",
+    "the moonlit door",
+];
+const TITLES: &[&str] = &["1024", "2048", "4096", "8192"];
+
+#[derive(Serialize)]
+struct DescCtx {
+    scroll_lines: Vec<String>,
+    weight: f64,
+    title: String,
+}
+
+impl Level for Tags {
+    fn id(&self) -> u8 {
+        8
+    }
+
+    fn name(&self) -> &'static str {
+        "Scroll of Tags"
+    }
+
+    fn generate(&self, seed: u64) -> Generated {
+        let mut rng = ChaCha8Rng::seed_from_u64(seed ^ 0x0000_0000_0000_0008);
+
+        let line_n = 2;
+        let scroll_lines: Vec<String> = (0..line_n)
+            .map(|_| {
+                let v = VERBS.choose(&mut rng).unwrap();
+                let n = NOUNS.choose(&mut rng).unwrap();
+                format!("{v} {n}.")
+            })
+            .collect();
+        // Block scalar `|` produces a string ending in `\n` after the last line.
+        let scroll_text = format!("{}\n", scroll_lines.join("\n"));
+
+        // Fractional weight so serde_yaml's float serialisation keeps the
+        // `.5` and matches the player's submission unambiguously.
+        let weight = rng.gen_range(1..=20) as f64 + 0.5;
+        let title = TITLES.choose(&mut rng).unwrap().to_string();
+
+        let mut top = Mapping::new();
+        top.insert(
+            Value::String("scroll".to_string()),
+            Value::String(scroll_text),
+        );
+        top.insert(Value::String("weight".to_string()), Value::from(weight));
+        top.insert(
+            Value::String("title".to_string()),
+            Value::String(title.clone()),
+        );
+
+        let target_yaml =
+            serde_yaml::to_string(&Value::Mapping(top)).expect("serialise mapping");
+
+        let mut d = Describer::new();
+        d.register(
+            "l08",
+            "A scroll demands its types. Match exactly:\n\
+             scroll: multi-line text{% for line in scroll_lines %}\n  {{ line }}{% endfor %}\n\
+             weight: must parse as the float {{ weight }}\n\
+             title:  must parse as the string \"{{ title }}\"\n\
+             💡 Block scalar `|` preserves newlines; `!!str` (or quotes) forces a digit-only string.",
+        )
+        .expect("register template");
+        let description = d
+            .render(
+                "l08",
+                &DescCtx {
+                    scroll_lines,
+                    weight,
+                    title,
+                },
+            )
+            .expect("render template");
+
+        Generated {
+            target_yaml,
+            description,
+            flavor: "📜 An ancient scroll insists on its precise form.".to_string(),
+        }
+    }
+}

src/levels/mod.rs

@@ -13,7 +13,7 @@
 pub mod l01_minimum;
 pub mod l02_kv;
 pub mod l03_dict;
-pub mod l05_dict_list;
+pub mod l08_tags;
 
 use serde::{Deserialize, Serialize};