Enhance playtesting and error handling in atlas skills

- Added a new `atlas-playtest` skill to automate quick playtesting in Roblox Studio, designed to catch runtime errors after code changes.
- Updated the `atlas-push` skill to automatically trigger the playtest after a successful push, ensuring immediate feedback on introduced errors.
- Enhanced the TODO list with detailed plans for error resolution and playtesting workflows, improving project management and user guidance.

These changes aim to streamline the development process by integrating automated testing and error handling into the workflow.

.cursor/skills/atlas-push/SKILL.md

@@ -176,6 +176,42 @@ Parse the response status:
 
 **Keep retrying** until sync succeeds or user explicitly says to stop. Each retry is safe because `studioHash` prevents clobbering.
 
+### Step 8: Post-Push Playtest
+
+**Skip this step** if the user's message contains "no test", "no playtest", "skip test", "no check", or "without testing".
+
+After a successful sync, automatically run a quick playtest to catch runtime errors introduced by the push.
+
+1. **Record pushed files.** Collect all `fsPath` values from changes where you pushed (direction `"push"` in the final sync response, or any script you merged and pushed). Also note the corresponding instance path segments (e.g. `src/server/GameManager.server.luau` corresponds to `ServerScriptService.GameManager`). You need these for error attribution.
+
+2. **Run the playtest:**
+
+```
+CallMcpTool:
+  server: "project-0-rojo-atlas"
+  toolName: "run_script_in_play_mode"
+  arguments: {
+    "code": "task.wait(7)\nprint(\"boot complete\")",
+    "mode": "start_play",
+    "timeout": 15
+  }
+```
+
+3. **Parse and filter errors.** From the response `errors` array, keep:
+   - All entries with level `"error"`
+   - Warnings that indicate real breakage ("Infinite yield possible", security errors)
+   - Ignore routine/cosmetic warnings, asset loading warnings, deprecation notices
+
+4. **Attribute errors to pushed files.** Roblox error messages include the script path, e.g.:
+   `ServerScriptService.GameManager.PlayerHandler:42: attempt to index nil`
+
+   Match the script name/path segments against your pushed `fsPath` list. Attribution is at the **whole-file level** -- if an error comes from a script we pushed, it's ours even if the erroring line wasn't part of our specific diff. Our change may have broken something else in that file.
+
+5. **Handle errors:**
+   - **Our errors** (originate from a pushed file): read the script, diagnose the error using the message and line number, fix the code, write the corrected file, then **loop back to Step 1** (dryrun the fix, sync it, re-test). Keep looping until the playtest is clean.
+   - **Others' errors** (no match to any pushed file): ask the user. Show the error, explain it doesn't originate from files we pushed, and recommend they investigate in a planning phase. Let the user decide via text input what to do. Do not auto-fix code you didn't push.
+   - **No errors**: report success. Push and playtest complete.
+
 ## Safety Invariants
 
 1. **Never sync without a dryrun first** -- always review what will change.