Add Pathfinder 2e game system mode

Implements PF2e as an alternative game system alongside D&D 5e/5.5e.
Settings modal "Game System" selector switches conditions, bestiary,
stat block layout, and initiative calculation between systems.

- Valued conditions with increment/decrement UX (Clumsy 2, Frightened 3)
- 2,502 PF2e creatures from bundled search index (77 sources)
- PF2e stat block: level, traits, Perception, Fort/Ref/Will, ability mods
- Perception-based initiative rolling
- System-scoped source cache (D&D and PF2e sources don't collide)
- Backwards-compatible condition rehydration (ConditionId[] → ConditionEntry[])
- Difficulty indicator hidden in PF2e mode (excluded from MVP)

Closes dostulata/initiative#19

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/components/combatant-row.tsx

@@ -1,6 +1,6 @@
 import {
 	type CombatantId,
-	type ConditionId,
+	type ConditionEntry,
 	type CreatureId,
 	deriveHpStatus,
 	type PlayerIcon,
@@ -31,7 +31,7 @@ interface Combatant {
 	readonly currentHp?: number;
 	readonly tempHp?: number;
 	readonly ac?: number;
-	readonly conditions?: readonly ConditionId[];
+	readonly conditions?: readonly ConditionEntry[];
 	readonly isConcentrating?: boolean;
 	readonly color?: string;
 	readonly icon?: string;
@@ -448,6 +448,8 @@ export function CombatantRow({
 		setTempHp,
 		setAc,
 		toggleCondition,
+		setConditionValue,
+		decrementCondition,
 		toggleConcentration,
 	} = useEncounterContext();
 	const { selectedCreatureId, showCreature, toggleCollapse } =
@@ -585,6 +587,7 @@ export function CombatantRow({
 						<ConditionTags
 							conditions={combatant.conditions}
 							onRemove={(conditionId) => toggleCondition(id, conditionId)}
+							onDecrement={(conditionId) => decrementCondition(id, conditionId)}
 							onOpenPicker={() => setPickerOpen((prev) => !prev)}
 						/>
 					</div>
@@ -593,6 +596,9 @@ export function CombatantRow({
 							anchorRef={conditionAnchorRef}
 							activeConditions={combatant.conditions}
 							onToggle={(conditionId) => toggleCondition(id, conditionId)}
+							onSetValue={(conditionId, value) =>
+								setConditionValue(id, conditionId, value)
+							}
 							onClose={() => setPickerOpen(false)}
 						/>
 					)}