✨Feature: add character creation logic and tests

- Implement character creation functions to handle adventurer setup.
- Add validation for adventurer name and selection of starting items.
- Introduce new items in sample content pack: Flint and Steel, Pouch, Wax Sealing Kit, and Backpack.
- Create tests for character creation functionality to ensure valid options and error handling.

✨Feature: implement dice rolling mechanics and tests

- Add functions for rolling various dice types (d3, d6, 2d6, d66) with validation.
- Implement modifier application with clamping for roll results.
- Create tests to verify correct behavior of dice rolling functions.

✨Feature: add table lookup functionality and tests

- Implement table lookup and resolution logic for defined tables.
- Support for modified ranges and fallback to nearest entries.
- Create tests to ensure correct table entry resolution based on roll results.

src/rules/character.ts

@@ -0,0 +1,128 @@
+import type { ContentPack } from "@/types/content";
+import type { AdventurerState, InventoryEntry } from "@/types/state";
+
+export type CharacterCreationChoiceSet = {
+  name: string;
+  weaponId: string;
+  armourId: string;
+  scrollId: string;
+};
+
+const DEFAULT_STARTING_ITEM_IDS = [
+  "item.flint-and-steel",
+  "item.lantern",
+  "item.ration",
+  "item.pouch",
+  "item.wax-sealing-kit",
+  "item.backpack",
+];
+
+function requireDefinition<T extends { id: string }>(
+  entries: T[],
+  id: string,
+  label: string,
+) {
+  const entry = entries.find((candidate) => candidate.id === id);
+
+  if (!entry) {
+    throw new Error(`Unknown ${label} id: ${id}`);
+  }
+
+  return entry;
+}
+
+function makeInventoryEntry(definitionId: string, quantity = 1): InventoryEntry {
+  return {
+    definitionId,
+    quantity,
+  };
+}
+
+export function getCharacterCreationOptions(content: ContentPack) {
+  return {
+    weapons: content.weapons.filter((weapon) => weapon.startingOption),
+    armour: content.armour.filter((armour) => armour.startingOption),
+    scrolls: content.scrolls.filter((scroll) => scroll.startingOption),
+  };
+}
+
+export function createStartingAdventurer(
+  content: ContentPack,
+  choices: CharacterCreationChoiceSet,
+): AdventurerState {
+  const trimmedName = choices.name.trim();
+
+  if (trimmedName.length === 0) {
+    throw new Error("Adventurer name is required.");
+  }
+
+  const selectedWeapon = requireDefinition(content.weapons, choices.weaponId, "weapon");
+  const selectedArmour = requireDefinition(content.armour, choices.armourId, "armour");
+  const selectedScroll = requireDefinition(content.scrolls, choices.scrollId, "scroll");
+
+  if (!selectedWeapon.startingOption) {
+    throw new Error(`Weapon ${selectedWeapon.id} is not a legal starting option.`);
+  }
+
+  if (!selectedArmour.startingOption) {
+    throw new Error(`Armour ${selectedArmour.id} is not a legal starting option.`);
+  }
+
+  if (!selectedScroll.startingOption) {
+    throw new Error(`Scroll ${selectedScroll.id} is not a legal starting option.`);
+  }
+
+  const allowedManoeuvreIds = selectedWeapon.allowedManoeuvreIds;
+
+  if (allowedManoeuvreIds.length === 0) {
+    throw new Error(`Weapon ${selectedWeapon.id} does not define starting manoeuvres.`);
+  }
+
+  DEFAULT_STARTING_ITEM_IDS.forEach((itemId) => requireDefinition(content.items, itemId, "item"));
+  requireDefinition(content.potions, "potion.healing", "potion");
+
+  return {
+    id: "adventurer.new",
+    name: trimmedName,
+    level: 1,
+    xp: 0,
+    hp: {
+      current: 10,
+      max: 10,
+      base: 10,
+    },
+    stats: {
+      shift: 2,
+      discipline: 1,
+      precision: 0,
+    },
+    weaponId: selectedWeapon.id,
+    manoeuvreIds: allowedManoeuvreIds,
+    armourId: selectedArmour.id,
+    favour: {},
+    statuses: [],
+    inventory: {
+      carried: [
+        makeInventoryEntry("item.flint-and-steel"),
+        makeInventoryEntry("item.lantern"),
+        makeInventoryEntry("item.ration", 3),
+        makeInventoryEntry("item.pouch"),
+        makeInventoryEntry("item.wax-sealing-kit"),
+        makeInventoryEntry("item.backpack"),
+        makeInventoryEntry(selectedScroll.id),
+        makeInventoryEntry("potion.healing"),
+      ],
+      equipped: [
+        makeInventoryEntry(selectedWeapon.id),
+        makeInventoryEntry(selectedArmour.id),
+      ],
+      stored: [],
+      currency: {
+        gold: 0,
+      },
+      rationCount: 3,
+      lightSources: [makeInventoryEntry("item.lantern")],
+    },
+    progressionFlags: [],
+  };
+}