Use one instance count for all beta games

docs/guides/beta-test-plans.md

@@ -12,16 +12,17 @@ file applies to all participants. Every file needs at least one matching test
 participant. For example, a T5 script and a T6 script can share one beta without
 either script being installed on the other game's servers.
 
-Setup defaults to automatic selection with one instance per applicable game.
-Choose the number that must pass for each game. Every automatically selected
-instance must pass every requirement in the plan. Set a game's count to zero to
-omit it only when every selected file still has a matching participant.
+Setup defaults to automatic selection. Enter one **Instances per game** number,
+which defaults to 1 and applies to every game represented by the selected files
+and their matching servers. Every automatically selected instance must pass
+every requirement in the plan.
 
 When you choose **Start beta**, Electric Cherry chooses compatible servers with
 the fewest current players, while ensuring that every file is tested. Counts
-are exact: requesting two T5 and three T6 instances selects five participants,
-and all five must pass. Server choices are made at launch, so review shows the
-requested counts rather than a provisional list of server names.
+are exact: with T5 and T6 files selected, entering 2 selects two T5 and two T6
+participants, and all four must pass. Server choices are made at launch, so
+review shows the count for each game rather than a provisional list of server
+names.
 
 Automatic selection requires fresh player observations and available running
 servers. Servers held by another active beta or with pending deployment work
@@ -34,8 +35,8 @@ empty lobbies and restart capacity.
 Open **Advanced options → Choose specific servers** for manual selection. The
 picker includes servers matching any file in the bundle; each file must have a
 matching selected server. Manual selection retains the configurable coverage
-rules below. Drafts preserve the selection mode and counts, and older drafts
-with explicit server choices resume in manual mode.
+rules below. Drafts preserve the selection mode and shared instance count, and
+older drafts with explicit server choices resume in manual mode.
 
 ## Game reporter protocol
 
@@ -324,10 +325,11 @@ changing the policy still requires a new beta.
 ## API and storage
 
 `POST /api/betas` accepts `scripts`, `testPlan`, and either
-`instancesPerGame` (for example, `{ "t5": 2, "t6": 3 }`) for automatic selection
+`instancesPerGame` (for example, `{ "t5": 2, "t6": 2 }`) for automatic selection
 or `servers` with explicit registered server names for manual selection. Submit
-only positive integer counts in `instancesPerGame`; omit games set to zero in
-the UI. Automatic selection sets the plan's coverage `scope` to `all`.
+only positive integer counts in `instancesPerGame`. The setup UI sends the same
+shared count for every applicable game; API clients can still supply different
+counts per game. Automatic selection sets the plan's coverage `scope` to `all`.
 Do not send both selection forms. File scopes determine which bundle files each
 participant receives in both modes.
 `GET /api/betas/:id` includes the plan, outcome, per-server progress, and