Retire sync live target apply mode

[cbusillo]

Retire Sync Live Target Apply Mode

Summary

• retire the local environments sync-live-target --apply mutation mode
• keep environments sync-live-target as a read-only tracked source/env drift preview
• update tests and docs to point shared/production mutation at the
  POST /v1/live-target-runtime/apply service route and workflow

Refs #1322

Validation

• focused sync-live-target retirement tests
• uv run python -m unittest tests.test_dokploy
• uv run python -m unittest tests.test_runtime_environments
• uv run python -m unittest
• uv run --extra dev ruff check on changed Python files
• uv run --extra dev ruff format --check on changed Python files
• uv run --extra dev mypy control_plane tests
• uv run --extra dev ruff check .
• uv run launchplane service audit-config-authority --control-plane-root .
• JetBrains changed-files closeout through the route-safe helper
• Review agents: antigravity, claude-sonnet-4.6, code-gpt-5.5 all green;
  merge recommended