GRM-161: Fix register.yml service start and bump devx to v0.50.5 (#238)

- Fix register.yml premature service start (removed systemctl start before unit file exists)
- Replace broken inline Python in ci.yml auto-merge with devx.ci.wait_for_checks
- Bump devx from v0.50.0 to v0.50.5

GRM-161

CHANGELOG.md

@@ -2,6 +2,24 @@
 
 All notable changes to this project will be documented in this file.
 
+## [Unreleased]
+
+### Bug Fixes
+
+- Fix `register.yml` premature service start: removed step that ran
+  `systemctl --user start gitea-runner` before the systemd unit file was
+  created by `service.yml` (included after `register.yml`). First-time
+  installs were failing with "Unit gitea-runner.service not found".
+- Fix `ci.yml` auto-merge IndentationError: replaced broken inline Python
+  polling script with `devx.ci.wait_for_checks` (the inline Python had
+  YAML run-block indentation leaking into `python3 -c` string).
+
+### Dependencies
+
+- Bump devx from v0.50.0 to v0.50.5 (adds `wait_for_checks` tool,
+  consolidated Ansible checks, tenacity retry in `install_tools`,
+  increased download retry attempts/backoff)
+
 ## [0.20.0] - 2026-08-09
 
 ### Features