chore(pack): mark Distant Horizons as an optional mod

Adds an [option] block so Distant Horizons is a user-toggleable mod instead
of always installed, matching how Controlify is already declared.

default = false expresses opt-in wherever the consuming exporter supports
it: modrinth/export.go reads only Optional, so in an mrpack the mod becomes
a toggle (that format has no off-by-default concept), while
curseforge/export.go reads Default and marks it optional-and-disabled.

Nothing in the pack depends on or conflicts with Distant Horizons, so no
other mod is left unsatisfied by it being skippable.

index.toml

@@ -212,7 +212,7 @@ metafile = true
 
 [[files]]
 file = "mods/distanthorizons.pw.toml"
-hash = "6d3e312dbf8db12dd1b6fb3bd1d29f210ab48024a0b2ebdf02fd32c265955c5d"
+hash = "7fd6d5b01ee6f20585b0a0b704f54c9f05772381bdbcbde30538452514774eb9"
 metafile = true
 
 [[files]]

mods/distanthorizons.pw.toml

@@ -2,6 +2,11 @@ name = "Distant Horizons"
 filename = "DistantHorizons-3.3.2-1.21.1-fabric-neoforge.jar"
 side = "both"
 
+[option]
+optional = true
+default = false
+description = "Extended render distance via level-of-detail terrain (heavy on GPU/VRAM)"
+
 [download]
 url = "https://cdn.modrinth.com/data/uCdwusMi/versions/Ez3cx7Yd/DistantHorizons-3.3.2-1.21.1-fabric-neoforge.jar"
 hash-format = "sha512"

pack.toml

@@ -6,7 +6,7 @@ pack-format = "packwiz:1.1.0"
 [index]
 file = "index.toml"
 hash-format = "sha256"
-hash = "b39ae3e18dd3f48977aee61c3bd1c9b2693facfa7aaab341e2bb1086b78a15a3"
+hash = "7d758d2aeb2da1f75c664ca98d55490febfede6c7dcd3db277595134350de168"
 
 [versions]
 minecraft = "1.21.1"