Fix install of bought games and launch of games with spaces in paths

Three bugs, all seen on Bubble Tower (itch.io game 4845491):

- Installs of bought games failed with "you must buy this game to download".
  butlerd only learns itch.io download keys from Fetch.ProfileOwnedKeys,
  which the library skips when "show_purchases" is off (the listing then
  comes from collections, so owned games still show up). butlerd queued
  the install without credentials and itch.io rejected the build request.
  Install.Queue is now retried once after a fresh owned-keys sync when
  itch.io answers with that error.

- The install-options upload dropdown never applied the user's pick: it
  offers "<name>  (<size>)" while _pick_upload compared against the bare
  displayName/filename, so every multi-upload game silently fell back to
  the default upload. The label format is now shared through
  UPLOAD_SIZE_SEPARATOR and the name prefix counts as a match.

- Games whose receipt carries no launch block were resolved by scanning
  for the largest executable and splitting "size path" on a space, which
  truncated the path of any file with a space in its name (Unity's
  "unity default resources") and pointed the launch at a file that does
  not exist. Sizes and paths are now tab-separated, and Unity's data
  files are skipped.

core/itch_client.gd

@@ -16,6 +16,10 @@ extends NodeThread
 ## butler update that changes a field, diff against that spec.
 
 const broth_base := "https://broth.itch.zone/butler"
+## Separator between an upload name and its size in the install-options
+## dropdown ("bubble-tower-linux.zip  (31.3 MB)"). Shared with the library so
+## the value the user picks can be matched back to the upload it came from.
+const UPLOAD_SIZE_SEPARATOR := "  ("
 ## Persistent storage for the downloaded butler binary + butler.db. Kept OUT
 ## of user://plugins/<id>/ because OGPU wipes that directory (and everything
 ## inside it) whenever the plugin is updated or re-extracted.
@@ -725,6 +729,47 @@ func _resolve_cave(game: Dictionary, cave_id: String) -> String:
 	return ""
 
 
+## Asks butlerd to queue an install of `upload` for `game`.
+func _queue_install(
+	game: Dictionary, upload: Dictionary, location_id: String, reason: String, cave_id: String
+) -> Dictionary:
+	var queue_params := {
+		"game": game,
+		"upload": upload,
+		"installLocationId": location_id,
+		"reason": reason,
+		"queueDownload": true,
+	}
+	if cave_id != "":
+		queue_params["caveId"] = cave_id
+	return await _rpc_call("Install.Queue", queue_params)
+
+
+## itch.io's answer when butlerd asks for a build without a download key the
+## account holds: the game is in the library but butlerd never learned its key.
+const ITCHIO_MISSING_DOWNLOAD_KEY_ERROR := "you must buy this game to download"
+
+
+func _is_missing_download_key_error(queue_res: Dictionary) -> bool:
+	if not queue_res.has("error"):
+		return false
+	return ITCHIO_MISSING_DOWNLOAD_KEY_ERROR in _rpc_error_message(queue_res)
+
+
+## butlerd only learns the itch.io download keys from Fetch.ProfileOwnedKeys.
+## When that call never ran (or ran long ago), butlerd queues installs without
+## credentials and itch.io rejects them, so pull a fresh copy of the keys.
+func _sync_owned_keys() -> void:
+	if not is_logged_in:
+		return
+	var profile_id: int = int(profile.get("user", {}).get("id", profile.get("id", 0)))
+	if profile_id == 0:
+		return
+	var res := await _rpc_call("Fetch.ProfileOwnedKeys", {"profileId": profile_id, "fresh": true})
+	if "error" in res:
+		logger.warn("Fetch.ProfileOwnedKeys (fresh) failed: " + str(res["error"]))
+
+
 func _install(game: Dictionary, cave_id: String, options: Dictionary) -> bool:
 	var game_id: int = game.get("id", 0)
 	cave_id = await _resolve_cave(game, cave_id)
@@ -756,17 +801,14 @@ func _install(game: Dictionary, cave_id: String, options: Dictionary) -> bool:
 	if location_id == "":
 		location_id = await _ensure_install_location()
 
-	var queue_params := {
-		"game": game,
-		"upload": upload,
-		"installLocationId": location_id,
-		"reason": reason,
-		"queueDownload": true,
-	}
-	if cave_id != "":
-		queue_params["caveId"] = cave_id
-
-	var queue_res := await _rpc_call("Install.Queue", queue_params)
+	var queue_res := await _queue_install(game, upload, location_id, reason, cave_id)
+	# butlerd sends the build request without an itch.io download key when its
+	# database doesn't hold one for this game, and itch.io answers "you must buy
+	# this game to download". Sync the owned keys and give it one more try.
+	if _is_missing_download_key_error(queue_res):
+		logger.info("Install of game " + str(game_id) + " was rejected for lack of a download key. Syncing owned keys and retrying.")
+		await _sync_owned_keys()
+		queue_res = await _queue_install(game, upload, location_id, reason, cave_id)
 	if "error" in queue_res:
 		var queue_error: String = _rpc_error_message(queue_res)
 		logger.error("Install.Queue failed: " + str(queue_res["error"]))
@@ -906,15 +948,28 @@ func _wipe_dir(path: String) -> void:
 
 
 ## Returns the upload whose displayName or filename matches the user's pick
-## from the install-options dropdown, or {} when nothing matches.
-func _pick_upload(uploads: Array, chosen: String) -> Dictionary:
+## from the install-options dropdown, or {} when nothing matches. The dropdown
+## renders each upload as "<name>  (<size>)", so the bare name prefix counts as
+## a match too.
+static func _pick_upload(uploads: Array, chosen: String) -> Dictionary:
 	for u in uploads:
 		var upload: Dictionary = u
-		if upload.get("displayName", "") == chosen or upload.get("filename", "") == chosen:
+		if upload_name_matches(upload, chosen):
 			return upload
 	return {}
 
 
+## True when `chosen` (an install-options dropdown value) names `upload`.
+static func upload_name_matches(upload: Dictionary, chosen: String) -> bool:
+	for name_key in ["displayName", "filename"]:
+		var name: String = upload.get(name_key, "")
+		if name == "":
+			continue
+		if chosen == name or chosen.begins_with(name + UPLOAD_SIZE_SEPARATOR):
+			return true
+	return false
+
+
 ## Uninstalls the given cave. Returns true on success.
 func uninstall(cave_id: String) -> bool:
 	return await thread_group.exec(_uninstall.bind(cave_id))