diff --git a/main.lua b/main.lua
index 7b6fba4c..62175e4d 100644
--- a/main.lua
+++ b/main.lua
@@ -84,40 +84,8 @@ local closeEditor  -- forward declaration: openEditor hands it to the editor
 
 -- Drop CacheFs / Data / mod Runtime / Assets / LegacyCompat for one mounted
 -- version session (save editor or game).  closeEditor and returnToLauncher
--- both go through here so neither path can forget a singleton the other resets.
-local function teardownMountedSession(version)
-  if version then
-    require("src.import.CacheFs").unmountVersion(version)
-  end
-  require("src.core.Data"):unloadGenerated()
-  local Runtime = require("src.mods.Runtime")
-  if Runtime.reset then Runtime.reset() end
-  local Assets = require("src.render.Assets")
-  if Assets.installLoader then Assets.installLoader(nil) end
-  local okCompat, LegacyCompat = pcall(require, "src.mods.LegacyCompat")
-  if okCompat and LegacyCompat.reset then LegacyCompat.reset() end
-end
-
--- Evict every save-editor module from package.loaded without a hardcoded
--- panel whitelist.  Flat require names (App, Party, …) resolve under
--- tools/save-editor/; path-style keys may also appear.  A key is flushed
--- when it names a save-editor path or when tools/save-editor/{panels/}K.lua
--- exists for a flat name K -- new panels are picked up automatically.
-local function flushEditorPackageLoaded()
-  local fs = love and love.filesystem
-  local function isEditorFlat(name)
-    if not (fs and fs.getInfo) then return false end
-    if name:find("[./]") then return false end
-    return fs.getInfo("tools/save-editor/" .. name .. ".lua") ~= nil
-      or fs.getInfo("tools/save-editor/panels/" .. name .. ".lua") ~= nil
-  end
-  for k in pairs(package.loaded) do
-    if type(k) == "string"
-        and (k:find("save%-editor", 1, false) or isEditorFlat(k)) then
-      package.loaded[k] = nil
-    end
-  end
-end
+-- both go through SessionLifecycle so neither path forgets a singleton.
+local SessionLifecycle = require("src.core.SessionLifecycle")
 
 -- The editor's modules use flat names (require("Kit"), require("Party")), so
 -- their directories have to be on the require path.  It must be
@@ -194,9 +162,7 @@ local function openEditor(version, slotId)
   local okReq, appOrErr = pcall(require, "App")
   if not okReq then
     editorMode = false
-    if version then
-      require("src.import.CacheFs").unmountVersion(version)
-    end
+    SessionLifecycle.endEditorSession({ version = version, app = nil })
     restoreWindow()
     Importer = editorHost
     editorHost = nil
@@ -216,10 +182,7 @@ local function openEditor(version, slotId)
     editorMode = false
     if EditorApp.unload then pcall(EditorApp.unload) end
     EditorApp = nil
-    if version then
-      teardownMountedSession(version)
-    end
-    flushEditorPackageLoaded()
+    SessionLifecycle.endEditorSession({ version = version, app = nil })
     restoreWindow()
     Importer = editorHost
     editorHost = nil
@@ -238,13 +201,10 @@ end
 -- next Edit or Play does not inherit the editor's dead mod loader.
 function closeEditor()
   local version = editorVersion
+  local app = EditorApp
   editorMode = false
-  if EditorApp and EditorApp.unload then EditorApp.unload() end
   EditorApp = nil
-  if version then
-    teardownMountedSession(version)
-  end
-  flushEditorPackageLoaded()
+  SessionLifecycle.endEditorSession({ version = version, app = app })
   editorVersion = nil
   restoreWindow()
   Importer = editorHost
@@ -345,40 +305,14 @@ end
 local function returnToLauncher()
   if not Game then return end
 
-  pcall(function() require("src.core.Music").stop() end)
-  pcall(function() require("src.core.Sound").stop() end)
-  if package.loaded["src.core.ChipAudio"] then
-    pcall(package.loaded["src.core.ChipAudio"].shutdown)
-  end
-  if package.loaded["src.core.DiscordPresence"] then
-    pcall(package.loaded["src.core.DiscordPresence"].shutdown)
-  end
-  if package.loaded["src.core.gen2.Clock"] then
-    pcall(package.loaded["src.core.gen2.Clock"].shutdown)
-  end
-  if package.loaded["src.net.Gen1Tls"] then
-    pcall(package.loaded["src.net.Gen1Tls"].shutdown)
-  end
-  if love.audio and love.audio.stop then
-    pcall(love.audio.stop)
-  end
-  pcall(function() require("src.render.SecondScreen").setEnabled(false) end)
-
   local GameVersion = require("src.core.GameVersion")
   local currentVersion = GameVersion.get()
-  teardownMountedSession(currentVersion)
-
-  if Game.reset then
-    pcall(function() Game:reset() end)
-  end
+  SessionLifecycle.endGameSession(Game)
   Game = nil
   autopilot = nil
   driverCo = nil
 
-  local Input = require("src.core.Input")
-  local TouchControls = require("src.core.TouchControls")
-  Input:reset()
-  TouchControls:reset()
+  SessionLifecycle.endMountedSession(currentVersion)
 
   require("src.core.Orientation").applyOptions(
     require("src.core.SaveData").loadOptions())
@@ -1181,22 +1115,7 @@ function love.quit()
   pcall(function()
     require("src.core.DiscordPresence").shutdown()
   end)
-  -- LOVE waits for every live love.thread before the process exits, and both
-  -- background workers idle in a loop that only a "quit" command breaks, so
-  -- without this the process outlived the window and the next launch re-entered
-  -- the dead one instead of starting fresh (#339)
-  if package.loaded["src.core.ChipAudio"] then
-    pcall(package.loaded["src.core.ChipAudio"].shutdown)
-  end
-  if package.loaded["src.update.Check"] then
-    pcall(package.loaded["src.update.Check"].shutdown)
-  end
-  -- The launcher's fetch pool is the same story: its workers idle in
-  -- Channel:demand(), which never returns on its own, so a launcher that ever
-  -- touched the network would hang the process on exit (#339's shape again).
-  if package.loaded["src.net.Fetch"] then
-    pcall(package.loaded["src.net.Fetch"].shutdown)
-  end
+  SessionLifecycle.endProcess()
 end
 
 function love.filedropped(file)
diff --git a/src/core/ChipAudio.lua b/src/core/ChipAudio.lua
index b7b09faa..ef07d40e 100644
--- a/src/core/ChipAudio.lua
+++ b/src/core/ChipAudio.lua
@@ -371,7 +371,7 @@ function ChipAudio.shutdown()
   if workerReady and cmdCh then cmdCh:push({ cmd = "quit" }) end
   if worker then pcall(function() worker:wait() end) end
   worker, cmdCh, outCh = nil, nil, nil
-  workerReady = false
+  workerReady = nil
 end
 
 function ChipAudio.currentSource()
@@ -498,6 +498,8 @@ end
 -- program (20 §2 cache contract, chip music row)
 Assets.register(ChipAudio.invalidate)
 
+require("src.core.SessionLifecycle").registerProcessShutdown(ChipAudio.shutdown)
+
 -- ---------------------------------------------------------------------------
 -- one-shot effects (SFX, cries, low-health alarm): synchronous static Sources
 -- ---------------------------------------------------------------------------
diff --git a/src/core/Game.lua b/src/core/Game.lua
index b1b730b9..71ae4d68 100644
--- a/src/core/Game.lua
+++ b/src/core/Game.lua
@@ -1389,12 +1389,25 @@ function Game:reset()
   if self.stack and self.stack.clear then
     pcall(function() self.stack:clear() end)
   end
+  if self.world and self.world.release then
+    pcall(function() self.world:release() end)
+  end
+  if self._canvases then
+    for _, canvas in pairs(self._canvases) do
+      if canvas and canvas.release then pcall(canvas.release, canvas) end
+    end
+  end
   if self.renderer and self.renderer.releaseCanvases then
     pcall(function() self.renderer:releaseCanvases() end)
   end
   local keys = {}
   for key, value in pairs(self) do
     if type(value) ~= "function" then
+      if key ~= "world" and key ~= "renderer" and key ~= "_canvases" then
+        if type(value) == "table" and value.release then
+          pcall(value.release, value)
+        end
+      end
       keys[#keys + 1] = key
     end
   end
diff --git a/src/core/Game2.lua b/src/core/Game2.lua
index 4ab8a479..145c97ed 100644
--- a/src/core/Game2.lua
+++ b/src/core/Game2.lua
@@ -2130,9 +2130,25 @@ function Game2:reset()
   if self.stack and self.stack.clear then
     pcall(function() self.stack:clear() end)
   end
+  if self.world and self.world.release then
+    pcall(function() self.world:release() end)
+  end
+  if self._canvases then
+    for _, canvas in pairs(self._canvases) do
+      if canvas and canvas.release then pcall(canvas.release, canvas) end
+    end
+  end
+  if self.renderer and self.renderer.releaseCanvases then
+    pcall(function() self.renderer:releaseCanvases() end)
+  end
   local keys = {}
   for key, value in pairs(self) do
     if type(value) ~= "function" then
+      if key ~= "world" and key ~= "renderer" and key ~= "_canvases" then
+        if type(value) == "table" and value.release then
+          pcall(value.release, value)
+        end
+      end
       keys[#keys + 1] = key
     end
   end
diff --git a/src/core/SessionLifecycle.lua b/src/core/SessionLifecycle.lua
new file mode 100644
index 00000000..84508a67
--- /dev/null
+++ b/src/core/SessionLifecycle.lua
@@ -0,0 +1,101 @@
+-- Central session lifecycle orchestrator.  Subsystems register teardown hooks
+-- at module load (Assets release/invalidate bus, process shutdown below); the
+-- host only calls phase entry points.
+--
+-- Three tiers:
+--   mount  endMountedSession   — GPU release + CacheFs/Data/Runtime/Assets
+--   game   endGameSession      — audio + game:reset; workers stay alive
+--   process endProcess          — worker shutdown on real app exit (love.quit)
+--
+-- Hot reload (Assets.flush / installLoader) stays invalidate-only forever.
+
+local SessionLifecycle = {}
+
+local processShutdowns = {}
+
+function SessionLifecycle.registerProcessShutdown(fn)
+  processShutdowns[#processShutdowns + 1] = fn
+end
+
+-- Drop CacheFs / Data / mod Runtime / Assets / LegacyCompat for one mounted
+-- version session (save editor or game).  GPU release runs before soft
+-- invalidate via installLoader(nil).
+function SessionLifecycle.endMountedSession(version)
+  local Assets = require("src.render.Assets")
+  if Assets.releaseSession then Assets.releaseSession() end
+  if version then
+    require("src.import.CacheFs").unmountVersion(version)
+  end
+  require("src.core.Data"):unloadGenerated()
+  local Runtime = require("src.mods.Runtime")
+  if Runtime.reset then Runtime.reset() end
+  if Assets.installLoader then Assets.installLoader(nil) end
+  local okCompat, LegacyCompat = pcall(require, "src.mods.LegacyCompat")
+  if okCompat and LegacyCompat.reset then LegacyCompat.reset() end
+end
+
+-- Evict every save-editor module from package.loaded without a hardcoded
+-- panel whitelist.  Flat require names (App, Party, …) resolve under
+-- tools/save-editor/; path-style keys may also appear.
+local function flushEditorPackageLoaded()
+  local fs = love and love.filesystem
+  local function isEditorFlat(name)
+    if not (fs and fs.getInfo) then return false end
+    if name:find("[./]") then return false end
+    return fs.getInfo("tools/save-editor/" .. name .. ".lua") ~= nil
+      or fs.getInfo("tools/save-editor/panels/" .. name .. ".lua") ~= nil
+  end
+  for k in pairs(package.loaded) do
+    if type(k) == "string"
+        and (k:find("save%-editor", 1, false) or isEditorFlat(k)) then
+      package.loaded[k] = nil
+    end
+  end
+end
+
+function SessionLifecycle.endEditorSession(opts)
+  opts = opts or {}
+  if opts.app and opts.app.unload then pcall(opts.app.unload) end
+  flushEditorPackageLoaded()
+  if opts.version then
+    SessionLifecycle.endMountedSession(opts.version)
+  end
+end
+
+-- EXIT GAME / intent_game before dropping Game.  Stops audio and resets the
+-- live game instance so map/GPU holders are gone before endMountedSession.
+function SessionLifecycle.endGameSession(game)
+  pcall(function() require("src.core.Music").stop() end)
+  pcall(function() require("src.core.Sound").stop() end)
+  if package.loaded["src.core.ChipAudio"] then
+    pcall(package.loaded["src.core.ChipAudio"].shutdown)
+  end
+  if package.loaded["src.core.DiscordPresence"] then
+    pcall(package.loaded["src.core.DiscordPresence"].shutdown)
+  end
+  if package.loaded["src.core.gen2.Clock"] then
+    pcall(package.loaded["src.core.gen2.Clock"].shutdown)
+  end
+  if package.loaded["src.net.Gen1Tls"] then
+    pcall(package.loaded["src.net.Gen1Tls"].shutdown)
+  end
+  if love.audio and love.audio.stop then
+    pcall(love.audio.stop)
+  end
+  pcall(function() require("src.render.SecondScreen").setEnabled(false) end)
+
+  if game and game.reset then
+    pcall(function() game:reset() end)
+  end
+
+  local Input = require("src.core.Input")
+  local TouchControls = require("src.core.TouchControls")
+  Input:reset()
+  TouchControls:reset()
+end
+
+function SessionLifecycle.endProcess()
+  for _, fn in ipairs(processShutdowns) do pcall(fn) end
+end
+
+return SessionLifecycle
diff --git a/src/net/Fetch.lua b/src/net/Fetch.lua
index 2a987125..9e8562cf 100644
--- a/src/net/Fetch.lua
+++ b/src/net/Fetch.lua
@@ -227,7 +227,9 @@ function Fetch.shutdown()
   end
   for _, th in ipairs(workers) do pcall(function() th:wait() end) end
   workers = {}
-  cmdCh, resCh, quitCh, ready = nil, nil, nil, false
+  cmdCh, resCh, quitCh, ready = nil, nil, nil, nil
 end
 
+require("src.core.SessionLifecycle").registerProcessShutdown(Fetch.shutdown)
+
 return Fetch
diff --git a/src/render/Assets.lua b/src/render/Assets.lua
index afcc577b..3469d0f1 100644
--- a/src/render/Assets.lua
+++ b/src/render/Assets.lua
@@ -14,6 +14,8 @@ local Assets = {}
 local cache = {}
 -- downstream caches that must empty when the search path changes
 local invalidators = {}
+-- optional GPU release hooks for session end (never run on hot reload flush)
+local releasers = {}
 
 -- The loader bridge: overrideOrder() yields mods highest-priority-first
 -- and derivedPath(rel) yields an existing save/mod-derived/<id>/<rel>.
@@ -68,8 +70,18 @@ function Assets.imageData(path)
   return love.image.newImageData(Assets.resolve(path))
 end
 
-function Assets.register(invalidate)
-  invalidators[#invalidators + 1] = invalidate
+-- Register a cache invalidator, or { invalidate = fn, release = fn } when a
+-- module caches LOVE Images/Canvases and can eagerly free them at session end.
+-- release is optional and is NOT run on flush/invalidate (HotReload safe).
+-- MapLoader is the canonical split-hook example: invalidateAll clears tables
+-- without GPU release; releaseAll evicts every resident map renderer.
+function Assets.register(hooks)
+  if type(hooks) == "function" then
+    invalidators[#invalidators + 1] = hooks
+    return
+  end
+  if hooks.invalidate then invalidators[#invalidators + 1] = hooks.invalidate end
+  if hooks.release then releasers[#releasers + 1] = hooks.release end
 end
 
 -- hot reload's single entry point (20-developer-tooling): drop the central
@@ -82,6 +94,17 @@ end
 
 Assets.flush = Assets.invalidate
 
+-- In-process return-to-launcher / editor close: release central Images and
+-- run release hooks only.  Does not call invalidate hooks (MapLoader must
+-- keep invalidateAll separate from releaseAll).
+function Assets.releaseSession()
+  for _, img in pairs(cache) do
+    if img and img.release then pcall(img.release, img) end
+  end
+  cache = {}
+  for _, fn in ipairs(releasers) do pcall(fn) end
+end
+
 -- Loader:load hands over the live mod set once the merge is done.  Load
 -- order is priority ascending, so the search walks it backwards: the mod
 -- that wins the record merge wins the asset lookup too.
diff --git a/src/render/Renderer.lua b/src/render/Renderer.lua
index 5ed14d47..08ddbe21 100644
--- a/src/render/Renderer.lua
+++ b/src/render/Renderer.lua
@@ -117,6 +117,8 @@ function Renderer:releaseCanvases()
   self.worldOverride = nil
 end
 
+Renderer.release = Renderer.releaseCanvases
+
 function Renderer:init()
   -- 160x144 real pixels, never DPI-scaled: see src/render/PixelCanvas.lua
   -- (#208).  Every canvas below is sized in framebuffer pixels for the same
diff --git a/src/update/Check.lua b/src/update/Check.lua
index b918f2f3..938889e0 100644
--- a/src/update/Check.lua
+++ b/src/update/Check.lua
@@ -343,7 +343,9 @@ function Check.shutdown()
   if cmdCh then cmdCh:push({ cmd = "quit" }) end
   if worker then pcall(function() worker:wait() end) end
   worker, cmdCh, stateCh = nil, nil, nil
-  workerReady = false
+  workerReady = nil
 end
 
+require("src.core.SessionLifecycle").registerProcessShutdown(Check.shutdown)
+
 return Check
diff --git a/src/world/MapLoader.lua b/src/world/MapLoader.lua
index 0452fec0..c52e3ed4 100644
--- a/src/world/MapLoader.lua
+++ b/src/world/MapLoader.lua
@@ -114,12 +114,25 @@ function MapLoader.invalidateAll()
   lru = {}
 end
 
+-- Eagerly release every resident map's TileRenderer GPU objects.  Only safe
+-- when nothing live holds map instances (session end after game:reset).
+function MapLoader.releaseAll()
+  local ids = {}
+  for id in pairs(cache) do ids[#ids + 1] = id end
+  for _, id in ipairs(ids) do MapLoader.evict(id) end
+end
+
 -- kept as the pre-v2 name
 MapLoader.clearCache = MapLoader.invalidateAll
 
 -- the cached Map objects own the per-map TileRenderer instances, so a flush
 -- that skipped this one would leave live SpriteBatches built from the old
--- search path (14 cache-invalidation contract, rows 1 and 3)
-Assets.register(MapLoader.invalidateAll)
+-- search path (14 cache-invalidation contract, rows 1 and 3).  invalidateAll
+-- deliberately does NOT release GPU (hot reload / live overworld); releaseAll
+-- is the session-end path only.
+Assets.register({
+  invalidate = MapLoader.invalidateAll,
+  release = MapLoader.releaseAll,
+})
 
 return MapLoader
diff --git a/src/world/OverworldController.lua b/src/world/OverworldController.lua
index e0391b3f..1f02377d 100644
--- a/src/world/OverworldController.lua
+++ b/src/world/OverworldController.lua
@@ -228,6 +228,11 @@ function OverworldState.computeNeighbors(maps, rootId, hops, reachW, reachH)
   return out
 end
 
+function OverworldState:exit()
+  self.map = nil
+  self.neighbors = nil
+end
+
 function OverworldState:enter(mapId, x, y, facing, opts)
   Game = require("src.core.Game")
   Game.overworld = self
diff --git a/src/world/gen2/World.lua b/src/world/gen2/World.lua
index ef84997a..ec83fa7b 100644
--- a/src/world/gen2/World.lua
+++ b/src/world/gen2/World.lua
@@ -5257,6 +5257,37 @@ function World:dropMapImages(mapId)
   if self.connectionMaps then self.connectionMaps[mapId] = nil end
 end
 
+local function safeRelease(obj)
+  if obj and obj ~= false and obj.release then pcall(obj.release, obj) end
+end
+
+-- Eagerly free session-owned GPU caches.  Assets.image-backed atlases are
+-- nilled without release; unique bakes, strips, and roof composites are released.
+function World:release()
+  if self.mapImages then
+    for _, img in pairs(self.mapImages) do safeRelease(img) end
+    self.mapImages = {}
+  end
+  if self.scrollStrips then
+    for _, strip in pairs(self.scrollStrips) do safeRelease(strip) end
+    self.scrollStrips = {}
+  end
+  safeRelease(self.tiltCanvas)
+  self.tiltCanvas = nil
+  if self.grassAtlases then
+    for _, atlas in pairs(self.grassAtlases) do safeRelease(atlas) end
+    self.grassAtlases = {}
+  end
+  if self.atlasCache then
+    for key, atlas in pairs(self.atlasCache) do
+      if key:find("|", 1, true) then safeRelease(atlas) end
+    end
+    self.atlasCache = {}
+  end
+  self.animQuads = nil
+  self.connectionMaps = nil
+end
+
 -- LoadMapAttributes' refill, for every map the session has edited.  Neighbour
 -- strips share the same buffer on the cart, so a connection crossing reloads
 -- them too: this runs on any setMap, seamless or not.
diff --git a/tests/engine/android_host_extension_test.lua b/tests/engine/android_host_extension_test.lua
index 4033cbed..efe7a839 100644
--- a/tests/engine/android_host_extension_test.lua
+++ b/tests/engine/android_host_extension_test.lua
@@ -88,8 +88,13 @@ check(destroy < destroyTeardown and destroyTeardown < destroySuper,
 local mainFile = assert(io.open("main.lua", "rb"))
 local main = mainFile:read("*a")
 mainFile:close()
-check(main:find('require("src.render.SecondScreen").setEnabled(false)', 1, true),
-  "returning from a game disables mod-owned secondary output")
+check(main:find("SessionLifecycle.endGameSession", 1, true),
+  "returning from a game goes through SessionLifecycle.endGameSession")
+local lifecycleFile = assert(io.open("src/core/SessionLifecycle.lua", "rb"))
+local lifecycle = lifecycleFile:read("*a")
+lifecycleFile:close()
+check(lifecycle:find('require("src.render.SecondScreen").setEnabled(false)', 1, true),
+  "endGameSession disables mod-owned secondary output")
 
 check(not source:lower():find("openxr", 1, true),
   "generic Android activity must not require OpenXR")
diff --git a/tests/engine/launcher_session_teardown_test.lua b/tests/engine/launcher_session_teardown_test.lua
index 6ceee3e2..e63d3fd7 100644
--- a/tests/engine/launcher_session_teardown_test.lua
+++ b/tests/engine/launcher_session_teardown_test.lua
@@ -1,5 +1,5 @@
 -- In-process launcher session teardown: Game:reset, Renderer canvas release,
--- Runtime/Assets/LegacyCompat cleanup, and editor package.loaded discovery flush.
+-- SessionLifecycle mount/game tiers, and editor package.loaded discovery flush.
 --   luajit tests/engine/launcher_session_teardown_test.lua
 
 package.path = "./?.lua;./?/init.lua;" .. package.path
@@ -12,8 +12,12 @@ local Runtime = require("src.mods.Runtime")
 local Assets = require("src.render.Assets")
 local LegacyCompat = require("src.mods.LegacyCompat")
 local Game = require("src.core.Game")
+local Game2 = require("src.core.Game2")
 local Renderer = require("src.render.Renderer")
 local StateStack = require("src.core.StateStack")
+local SessionLifecycle = require("src.core.SessionLifecycle")
+local MapLoader = require("src.world.MapLoader")
+local World = require("src.world.gen2.World")
 
 -- ---- Game:reset drops instance state, keeps methods ----------------------
 do
@@ -38,6 +42,35 @@ do
   check(StateStack:top() == nil, "Game:reset cleared the shared StateStack")
 end
 
+-- ---- Game2:reset releases world GPU and present canvases ------------------
+do
+  local game2 = Game2.new()
+  local canvas = love.graphics.newCanvas(4, 4)
+  game2.world = World.new({})
+  game2.world.mapImages = { ["MAP|d|1"] = canvas }
+  game2._canvases = { love.graphics.newCanvas(8, 8) }
+  game2:reset()
+  check(canvas.released == true, "Game2:reset releases World mapImages")
+  check(game2.world == nil, "Game2:reset clears world reference")
+  check(game2._canvases == nil, "Game2:reset clears _canvases")
+end
+
+-- ---- World:release frees owned GPU caches --------------------------------
+do
+  local world = World.new({})
+  local bake = love.graphics.newCanvas(16, 16)
+  local strip = love.graphics.newCanvas(8, 64)
+  local tilt = love.graphics.newCanvas(160, 144)
+  world.mapImages = { ["R1|DAY|1"] = bake }
+  world.scrollStrips = { ["TS|1|0,0"] = strip }
+  world.tiltCanvas = tilt
+  world:release()
+  check(bake.released == true, "World:release frees map bake canvases")
+  check(strip.released == true, "World:release frees scroll strips")
+  check(tilt.released == true, "World:release frees tiltCanvas")
+  eq(next(world.mapImages), nil, "World:release clears mapImages table")
+end
+
 -- ---- Renderer:init releases prior canvases before realloc ----------------
 do
   local first = love.graphics.newCanvas(16, 16)
@@ -52,14 +85,13 @@ do
     "Renderer:init allocates a fresh primary canvas")
   check(Renderer.canvas.released ~= true,
     "the new primary canvas is not released")
-  -- second init also releases the one just created
   local second = Renderer.canvas
   Renderer:init()
   check(second.released == true,
     "a second Renderer:init releases the canvas from the prior init")
 end
 
--- ---- Shared singleton teardown contract (closeEditor / returnToLauncher)
+-- ---- SessionLifecycle.endMountedSession (closeEditor / returnToLauncher) --
 do
   Runtime.install({ emit = function() end }, { call = function() end }, { "e" })
   Assets.installLoader({
@@ -68,44 +100,79 @@ do
   })
   LegacyCompat.reports = { some_mod = { order = {} } }
 
-  -- Mirrors main.lua teardownMountedSession without mounting CacheFs.
-  require("src.core.Data"):unloadGenerated()
-  Runtime.reset()
-  Assets.installLoader(nil)
-  LegacyCompat.reset()
+  SessionLifecycle.endMountedSession(nil)
 
-  check(Runtime.errors == nil, "teardown clears Runtime.errors")
-  check(Assets.loader == nil, "teardown clears Assets.loader")
-  eq(next(LegacyCompat.reports), nil, "teardown clears LegacyCompat.reports")
+  check(Runtime.errors == nil, "endMountedSession clears Runtime.errors")
+  check(Assets.loader == nil, "endMountedSession clears Assets.loader")
+  eq(next(LegacyCompat.reports), nil, "endMountedSession clears LegacyCompat.reports")
 end
 
--- ---- Editor package.loaded discovery flush (no panel whitelist) ---------
+-- ---- releaseSession empties MapLoader via releaseAll, not flush -------------
+do
+  local data = {
+    maps = { T1 = { id = "T1", tileset = "TS", width = 1, height = 1,
+      blocks = { 0 }, borderBlock = 0, objects = {}, warps = {}, signs = {} } },
+    tilesets = { TS = { id = "TS", image = "assets/generated/t.png",
+      walkable = {}, blocks = { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } },
+      tilesPerRow = 1 } },
+  }
+  MapLoader.load(data, "T1")
+  check(MapLoader.cached("T1") ~= nil, "MapLoader holds a map before release")
+  Assets.releaseSession()
+  check(MapLoader.cached("T1") == nil,
+    "releaseSession evicts MapLoader via releaseAll")
+end
+
+-- ---- Editor package.loaded discovery flush via endEditorSession -----------
 do
   love.filesystem.write("tools/save-editor/App.lua", "return {}")
   love.filesystem.write("tools/save-editor/panels/NewPanel.lua", "return {}")
   package.loaded["App"] = { stale = true }
   package.loaded["NewPanel"] = { stale = true }
-  package.loaded["src.core.Data"] = package.loaded["src.core.Data"] -- keep
+  package.loaded["src.core.Data"] = package.loaded["src.core.Data"]
 
-  local function isEditorFlat(name)
-    if name:find("[./]") then return false end
-    return love.filesystem.getInfo("tools/save-editor/" .. name .. ".lua") ~= nil
-      or love.filesystem.getInfo("tools/save-editor/panels/" .. name .. ".lua") ~= nil
-  end
-  for k in pairs(package.loaded) do
-    if type(k) == "string"
-        and (k:find("save%-editor", 1, false) or isEditorFlat(k)) then
-      package.loaded[k] = nil
-    end
-  end
+  SessionLifecycle.endEditorSession({ version = nil, app = nil })
 
-  check(package.loaded["App"] == nil, "discovery flush drops flat App")
+  check(package.loaded["App"] == nil, "endEditorSession drops flat App")
   check(package.loaded["NewPanel"] == nil,
-    "discovery flush drops a new panel without a hardcoded list")
+    "endEditorSession drops a new panel without a hardcoded list")
   check(package.loaded["src.core.Data"] ~= nil,
-    "discovery flush leaves engine modules alone")
+    "endEditorSession leaves engine modules alone")
   love.filesystem.remove("tools/save-editor/App.lua")
   love.filesystem.remove("tools/save-editor/panels/NewPanel.lua")
 end
 
+-- ---- Fetch shutdown clears ready so Play-again can respawn workers ---------
+do
+  local Fetch = require("src.net.Fetch")
+  local spawnAttempts = 0
+  love.thread = love.thread or {}
+  local savedNewThread = love.thread.newThread
+  local savedGetChannel = love.thread.getChannel
+  love.thread.getChannel = function()
+    return {
+      clear = function() end,
+      push = function() end,
+      pop = function() return nil end,
+      demand = function() end,
+    }
+  end
+  love.thread.newThread = function()
+    spawnAttempts = spawnAttempts + 1
+    return {
+      start = function() end,
+      wait = function() end,
+      getError = function() return nil end,
+    }
+  end
+  Fetch.available()
+  local afterFirst = spawnAttempts
+  Fetch.shutdown()
+  Fetch.available()
+  check(spawnAttempts > afterFirst,
+    "Fetch.available retries worker spawn after shutdown (ready=nil)")
+  love.thread.newThread = savedNewThread
+  love.thread.getChannel = savedGetChannel
+end
+
 T.finish("launcher_session_teardown_test")
diff --git a/tests/engine/quit_thread_shutdown.lua b/tests/engine/quit_thread_shutdown.lua
index a0dff35b..4f8a3589 100644
--- a/tests/engine/quit_thread_shutdown.lua
+++ b/tests/engine/quit_thread_shutdown.lua
@@ -182,11 +182,20 @@ check(checkSrc:match('cmd%.cmd == "quit"%s*then%s*\n%s*break') ~= nil,
 local mainSrc = source("main.lua")
 local quitHook = mainSrc:match("\nfunction love%.quit%(%).-\nend\n")
 check(quitHook ~= nil, "love.quit is still a single top-level function")
-quitHook = quitHook or ""
-check(quitHook:find('package.loaded["src.core.ChipAudio"].shutdown', 1, true) ~= nil,
-      "love.quit shuts the chip worker down")
-check(quitHook:find('package.loaded["src.update.Check"].shutdown', 1, true) ~= nil,
-      "love.quit shuts the update worker down")
+check(mainSrc:find("SessionLifecycle.endProcess()", 1, true) ~= nil,
+      "love.quit shuts workers down via SessionLifecycle.endProcess")
+
+local lifecycleSrc = source("src/core/SessionLifecycle.lua")
+check(lifecycleSrc:find("registerProcessShutdown", 1, true) ~= nil,
+      "SessionLifecycle exposes registerProcessShutdown")
+check(lifecycleSrc:find("function SessionLifecycle.endProcess()", 1, true) ~= nil,
+      "SessionLifecycle.endProcess fans out registered hooks")
+check(source("src/core/ChipAudio.lua"):find("registerProcessShutdown(ChipAudio.shutdown)", 1, true) ~= nil,
+      "ChipAudio registers its shutdown hook at load")
+check(source("src/update/Check.lua"):find("registerProcessShutdown(Check.shutdown)", 1, true) ~= nil,
+      "Check registers its shutdown hook at load")
+check(source("src/net/Fetch.lua"):find("registerProcessShutdown(Fetch.shutdown)", 1, true) ~= nil,
+      "Fetch registers its shutdown hook at load")
 
 -- The Android half: LOVE keeps the JVM process after the native main returns,
 -- so the quit event exits the process outright.  It has to sit after the
diff --git a/tests/mod_graphics_tests.lua b/tests/mod_graphics_tests.lua
index 5b9ff89d..f60ac7d1 100644
--- a/tests/mod_graphics_tests.lua
+++ b/tests/mod_graphics_tests.lua
@@ -218,8 +218,12 @@ for name, module in pairs({ Assets = Assets, TileRenderer = TileRenderer,
 end
 check(type(require("src.world.MapLoader").invalidateAll) == "function",
       "MapLoader keeps its wave-1 invalidateAll")
+check(type(require("src.world.MapLoader").releaseAll) == "function",
+      "MapLoader exposes releaseAll for session end")
 check(type(require("src.core.Sound").invalidate) == "function",
       "Sound keeps its wave-1 invalidate")
+check(type(Assets.releaseSession) == "function",
+      "Assets exposes releaseSession for in-process session end")
 
 -- the central cache hands back one image per resolved path, and flush
 -- fans out to every registered downstream cache
@@ -240,6 +244,14 @@ Assets.register(function() reached = true end)
 Assets.flush()
 check(reached, "a throwing invalidator does not stop the fan-out")
 
+-- flush/invalidate must not run release hooks (HotReload / live overworld safe)
+local releaseCalls = 0
+Assets.register({ release = function() releaseCalls = releaseCalls + 1 end })
+Assets.flush()
+check(releaseCalls == 0, "flush() does not call release hooks")
+Assets.releaseSession()
+check(releaseCalls == 1, "releaseSession() calls registered release hooks")
+
 -- ------- animated tiles as tileset data
 
 local overworld = TileRenderer.defaultAnimatedTiles(