Pokemon Silver as a full launcher version, plus launcher mods-list and title-tempo fixes

Silver: derived import manifest (tools/make_silver_manifest.py re-resolves
the Gold manifest's symbols from pokesilver.sym), silver GameVersion row,
generation-keyed extractor routing, required-files override, edition save
stamping (a Silver playthrough no longer writes into the Gold save),
checkver-driven edition data, SILVER/KAMON/OSCAR/MAX presets, GOLD rival
default, edition credits banner, Lugia title screen (OAM layouts, bob,
trail, palettes as title.lua data keys with Gold defaults so old caches
need no re-import), packaging for every build target, docs, and tests.

Launcher: the installed-mods list is one continuous scroll (rows culled to
the viewport) instead of a pager with an inner scroll viewport; the pad
cursor's edge-scroll no longer runs it to the bottom. The game dropdown
shows just the initial and caret. Find-tab behavior unchanged.

Title tempo: a sprite-anim frame shows duration+1 ticks
(engine/sprite_anims/core.asm GetSpriteAnimFrame), which locks both
editions' 64-tick wing beat to the 64-tick sine bob; the title screens no
longer run fast and out of phase.

tests/gen2_halloffame_test.lua

@@ -31,10 +31,14 @@ require("src.core.Logger").warn = function() end
 
 local Core = require("src.core.gen2.HallOfFame")
 local Credits = require("src.ui.gen2.Credits")
+local GameVersion = require("src.core.GameVersion")
 local HallOfFame = require("src.ui.gen2.HallOfFame")
 local Save = require("src.core.gen2.Save")
 local Screens = require("src.ui.Screens")
 
+local priorVersion = GameVersion.get()
+GameVersion.set("gold")
+
 -- ---- fixtures -------------------------------------------------------------
 
 local POKEMON = {
@@ -711,4 +715,6 @@ else
   eq(creditsData.palettes[1][1][1], 255, "and set 1 colour 0 is white")
 end
 
+GameVersion.set(priorVersion)
+
 S.finish()