fix: CLI Play no longer rewrites unsaved Scene files; --unsaved-changes chooses keep, save, or fail

.agents/skills/uloop-control-play-mode/SKILL.md

@@ -20,6 +20,7 @@ uloop control-play-mode [options]
 |-----------|------|---------|-------------|
 | `--action` | string | `Play` | `Play` - start Play Mode, `Stop` - stop Play Mode, `Pause` - pause Play Mode, `Step` - advance one frame while paused, `Status` - report current state without changing anything, `Resume` - alias of Play in every state, including starting Play Mode when stopped |
 | `--timeout-seconds` | integer | `180` | Maximum seconds to wait for the requested play mode state |
+| `--unsaved-changes` | string | `keep` | How `Play` from Edit Mode handles unsaved Scene/Prefab Stage changes: `keep` enters Play Mode without saving (like the Editor's Play button); `save` writes them first; `fail` stops if any exist |
 
 ## Output
 
@@ -31,7 +32,7 @@ Returns JSON with the current play mode state:
 - `WasAlreadyStopped`: Whether `Stop` was requested while Play Mode was already stopped
 - `ResumedFromPause`: Whether `Play` resumed a paused Play Mode session instead of starting a new one
 - `Message`: Description of the action performed
-- `Warning` (string, optional): Set when the action carries a caveat. A fresh `Play` start always notes that the session started from Edit-time scene state; additionally, when active hot-reload patches or enabled pause points exist and Domain Reload is enabled, it reports how many of them the Play-entry domain reload will discard. Pause points enabled with `--persist` are counted separately: they are re-armed after the reload, and the warning points at `pause-point-status` for the re-arm result. `Status` also reports when Play Mode is running while the Unity Editor is unfocused, because progress may be throttled; run `uloop focus-window`, or use the `pause-point --await`/`--trigger` flow instead of polling for progress.
+- `Warning` (string, optional): Set when the action carries a caveat. With `--unsaved-changes save` it starts by listing every Scene and Prefab Stage it saved. A fresh `Play` start always notes that the session started from Edit-time scene state; additionally, when active hot-reload patches or enabled pause points exist and Domain Reload is enabled, it reports how many of them the Play-entry domain reload will discard. Pause points enabled with `--persist` are counted separately: they are re-armed after the reload, and the warning points at `pause-point-status` for the re-arm result. `Status` also reports when Play Mode is running while the Unity Editor is unfocused, because progress may be throttled; run `uloop focus-window`, or use the `pause-point --await`/`--trigger` flow instead of polling for progress.
 - `StoppedBy` (string, optional): Why Play Mode last stopped: `cli-control-play-mode`, `cli-compile-stop-setting`, `cli-run-tests-cancel`, `script-compilation`, or `unknown`. Present on `Stop` when Play Mode was already stopped, and on `Status` when Play Mode is not running. Omitted when this Editor session has no confirmed stop.
 - `StoppedAt` (string, optional): UTC ISO 8601 timestamp of that stop. Omitted together with `StoppedBy` when no stop is recorded.
 - `ActiveScenario` (string, optional): Name of the active non-default Play Mode configuration (for example a Multiplayer Play Mode scenario). Omitted when the default configuration is active.
@@ -45,7 +46,8 @@ Returns JSON with the current play mode state:
 - `Step` advances exactly one frame and leaves PlayMode paused (the Editor's Next Frame button); it is independent of `Time.timeScale` and requires PlayMode to be running
 - The command waits for the requested state before returning. Increase `--timeout-seconds` for projects with slow PlayMode entry.
 - Before relying on PlayMode behavior as verification evidence, check `uloop get-logs --log-type Error` for pre-existing errors. An error already present when PlayMode starts can otherwise be mistaken for one caused by the action under test.
-- `Status` reads the current state with no side effects: `Changed` is always `false`, no waiting, no scene saving, and it is never rejected by compile errors. It reports whether compile errors would currently block `Play` (`BlockedByCompileErrors` with the `CompileErrors` list), read from the last compile result without triggering a new compile. It does not predict unsaved-changes blocking: `BlockedByUnsavedChanges` describes a failed save attempt during a `Play` request, and `Status` never attempts one.
-- `Play` fails immediately with a `CONTROL_PLAY_MODE_UNSAVED_CHANGES` error when unsaved changes cannot be saved quietly — most commonly an Untitled scene, which has no path to save to. The error message lists exactly which scenes or prefab stages blocked it; save the Untitled scene to an explicit path (or discard the changes), then retry.
+- `Status` reads the current state with no side effects: `Changed` is always `false`, no waiting, no scene saving, and it is never rejected by compile errors. It reports whether compile errors would currently block `Play` (`BlockedByCompileErrors` with the `CompileErrors` list), read from the last compile result without triggering a new compile. It does not predict unsaved-changes blocking: `BlockedByUnsavedChanges` describes a `Play` request that `--unsaved-changes` stopped, and `Status` never checks.
+- `--unsaved-changes` applies only when `Play` enters Play Mode from Edit Mode; resuming a paused session never saves or checks. With the default `keep`, unsaved edits stay in memory: Unity restores them when Play Mode ends, and Scene files on disk are not rewritten.
+- `Play` fails immediately with a `CONTROL_PLAY_MODE_UNSAVED_CHANGES` error when `fail` finds unsaved changes, or when `save` cannot save them — most commonly an Untitled scene, which has no path to save to. The error message lists exactly which scenes or prefab stages blocked it; use `keep`, or save the Untitled scene to an explicit path (or discard the changes), then retry.
 - `Play` and `Stop` follow the active Play Mode configuration like the Editor's Play button: with a Multiplayer Play Mode scenario selected they start and stop its Virtual Players too. To find and command Virtual Players, read [references/multiplayer-play-mode.md](references/multiplayer-play-mode.md).
 - `Play` from Edit mode triggers a domain reload (unless Enter Play Mode Options disable it), which discards all active hot-reload patches and every enabled pause point; pause points enabled with `--persist` are then re-armed from their saved enable request. The response `Warning` reports the counts being dropped and, separately, how many re-arm. Edits that were only hot-reloaded are not part of the compiled assemblies, so the new session runs the last compiled code — run `uloop compile` before `Play` to keep them, or re-apply `uloop hot-reload` after Play Mode starts.

.agents/skills/uloop-control-play-mode/references/multiplayer-play-mode.md

@@ -59,5 +59,6 @@ main Editor) do not block each other.
   "Play Mode Scenario - Scenario Setup Error". The CLI cannot see that failure and waits for Play
   Mode until `--timeout-seconds` expires. Close the dialog in the Editor and read the Console
   errors (`uloop get-logs --log-type Error`).
-- Unsaved scenes are saved quietly before `Play`, as with the default configuration. An Untitled
-  scene still fails with `CONTROL_PLAY_MODE_UNSAVED_CHANGES`.
+- `--unsaved-changes` applies as with the default configuration: `keep` (the default) starts
+  without saving, `save` writes unsaved scenes first (an Untitled scene then fails with
+  `CONTROL_PLAY_MODE_UNSAVED_CHANGES`), and `fail` stops if any exist.

.claude/skills/uloop-control-play-mode/SKILL.md

@@ -20,6 +20,7 @@ uloop control-play-mode [options]
 |-----------|------|---------|-------------|
 | `--action` | string | `Play` | `Play` - start Play Mode, `Stop` - stop Play Mode, `Pause` - pause Play Mode, `Step` - advance one frame while paused, `Status` - report current state without changing anything, `Resume` - alias of Play in every state, including starting Play Mode when stopped |
 | `--timeout-seconds` | integer | `180` | Maximum seconds to wait for the requested play mode state |
+| `--unsaved-changes` | string | `keep` | How `Play` from Edit Mode handles unsaved Scene/Prefab Stage changes: `keep` enters Play Mode without saving (like the Editor's Play button); `save` writes them first; `fail` stops if any exist |
 
 ## Output
 
@@ -31,7 +32,7 @@ Returns JSON with the current play mode state:
 - `WasAlreadyStopped`: Whether `Stop` was requested while Play Mode was already stopped
 - `ResumedFromPause`: Whether `Play` resumed a paused Play Mode session instead of starting a new one
 - `Message`: Description of the action performed
-- `Warning` (string, optional): Set when the action carries a caveat. A fresh `Play` start always notes that the session started from Edit-time scene state; additionally, when active hot-reload patches or enabled pause points exist and Domain Reload is enabled, it reports how many of them the Play-entry domain reload will discard. Pause points enabled with `--persist` are counted separately: they are re-armed after the reload, and the warning points at `pause-point-status` for the re-arm result. `Status` also reports when Play Mode is running while the Unity Editor is unfocused, because progress may be throttled; run `uloop focus-window`, or use the `pause-point --await`/`--trigger` flow instead of polling for progress.
+- `Warning` (string, optional): Set when the action carries a caveat. With `--unsaved-changes save` it starts by listing every Scene and Prefab Stage it saved. A fresh `Play` start always notes that the session started from Edit-time scene state; additionally, when active hot-reload patches or enabled pause points exist and Domain Reload is enabled, it reports how many of them the Play-entry domain reload will discard. Pause points enabled with `--persist` are counted separately: they are re-armed after the reload, and the warning points at `pause-point-status` for the re-arm result. `Status` also reports when Play Mode is running while the Unity Editor is unfocused, because progress may be throttled; run `uloop focus-window`, or use the `pause-point --await`/`--trigger` flow instead of polling for progress.
 - `StoppedBy` (string, optional): Why Play Mode last stopped: `cli-control-play-mode`, `cli-compile-stop-setting`, `cli-run-tests-cancel`, `script-compilation`, or `unknown`. Present on `Stop` when Play Mode was already stopped, and on `Status` when Play Mode is not running. Omitted when this Editor session has no confirmed stop.
 - `StoppedAt` (string, optional): UTC ISO 8601 timestamp of that stop. Omitted together with `StoppedBy` when no stop is recorded.
 - `ActiveScenario` (string, optional): Name of the active non-default Play Mode configuration (for example a Multiplayer Play Mode scenario). Omitted when the default configuration is active.
@@ -45,7 +46,8 @@ Returns JSON with the current play mode state:
 - `Step` advances exactly one frame and leaves PlayMode paused (the Editor's Next Frame button); it is independent of `Time.timeScale` and requires PlayMode to be running
 - The command waits for the requested state before returning. Increase `--timeout-seconds` for projects with slow PlayMode entry.
 - Before relying on PlayMode behavior as verification evidence, check `uloop get-logs --log-type Error` for pre-existing errors. An error already present when PlayMode starts can otherwise be mistaken for one caused by the action under test.
-- `Status` reads the current state with no side effects: `Changed` is always `false`, no waiting, no scene saving, and it is never rejected by compile errors. It reports whether compile errors would currently block `Play` (`BlockedByCompileErrors` with the `CompileErrors` list), read from the last compile result without triggering a new compile. It does not predict unsaved-changes blocking: `BlockedByUnsavedChanges` describes a failed save attempt during a `Play` request, and `Status` never attempts one.
-- `Play` fails immediately with a `CONTROL_PLAY_MODE_UNSAVED_CHANGES` error when unsaved changes cannot be saved quietly — most commonly an Untitled scene, which has no path to save to. The error message lists exactly which scenes or prefab stages blocked it; save the Untitled scene to an explicit path (or discard the changes), then retry.
+- `Status` reads the current state with no side effects: `Changed` is always `false`, no waiting, no scene saving, and it is never rejected by compile errors. It reports whether compile errors would currently block `Play` (`BlockedByCompileErrors` with the `CompileErrors` list), read from the last compile result without triggering a new compile. It does not predict unsaved-changes blocking: `BlockedByUnsavedChanges` describes a `Play` request that `--unsaved-changes` stopped, and `Status` never checks.
+- `--unsaved-changes` applies only when `Play` enters Play Mode from Edit Mode; resuming a paused session never saves or checks. With the default `keep`, unsaved edits stay in memory: Unity restores them when Play Mode ends, and Scene files on disk are not rewritten.
+- `Play` fails immediately with a `CONTROL_PLAY_MODE_UNSAVED_CHANGES` error when `fail` finds unsaved changes, or when `save` cannot save them — most commonly an Untitled scene, which has no path to save to. The error message lists exactly which scenes or prefab stages blocked it; use `keep`, or save the Untitled scene to an explicit path (or discard the changes), then retry.
 - `Play` and `Stop` follow the active Play Mode configuration like the Editor's Play button: with a Multiplayer Play Mode scenario selected they start and stop its Virtual Players too. To find and command Virtual Players, read [references/multiplayer-play-mode.md](references/multiplayer-play-mode.md).
 - `Play` from Edit mode triggers a domain reload (unless Enter Play Mode Options disable it), which discards all active hot-reload patches and every enabled pause point; pause points enabled with `--persist` are then re-armed from their saved enable request. The response `Warning` reports the counts being dropped and, separately, how many re-arm. Edits that were only hot-reloaded are not part of the compiled assemblies, so the new session runs the last compiled code — run `uloop compile` before `Play` to keep them, or re-apply `uloop hot-reload` after Play Mode starts.

.claude/skills/uloop-control-play-mode/references/multiplayer-play-mode.md

@@ -59,5 +59,6 @@ main Editor) do not block each other.
   "Play Mode Scenario - Scenario Setup Error". The CLI cannot see that failure and waits for Play
   Mode until `--timeout-seconds` expires. Close the dialog in the Editor and read the Console
   errors (`uloop get-logs --log-type Error`).
-- Unsaved scenes are saved quietly before `Play`, as with the default configuration. An Untitled
-  scene still fails with `CONTROL_PLAY_MODE_UNSAVED_CHANGES`.
+- `--unsaved-changes` applies as with the default configuration: `keep` (the default) starts
+  without saving, `save` writes unsaved scenes first (an Untitled scene then fails with
+  `CONTROL_PLAY_MODE_UNSAVED_CHANGES`), and `fail` stops if any exist.