Implements world_persistence_impl.md §9 client/editor task items 2-3:
- ChunkSaveService (scripts/editor/chunk_save_service.gd): single-chunk
PUT with base_revision, batch PUT for multi-chunk edits, and a real
409 -> re-fetch -> retry loop. Full-chunk overwrite (§8.2 D5) means
"re-apply the edit" is just retrying with the locally-edited payload
at the freshly-learned revision, not delta replay.
- InGameEditor gets a Save button (+ Ctrl+S) that surfaces live_session
as an explicit warning instead of ignoring it, per §6 D4.
- "Edit World" entry point on the world list (owner-gated) that calls
Session.begin_edit() instead of ApiClient.join_world() -- editing
never joins, opens no ENet connection, spawns no dedicated server.
- game.gd wires Session.editing to fetch the real (0,0,0) chunk over
HTTP and open the editor against it, falling back to an empty chunk
for an unwritten coordinate.
Verified against a real backend (register/world/save/reload, a genuine
409 from two racing saves, atomic 2-chunk batch, live_session field) --
new scripts/smoke_test_editor_save.gd (19/19) plus an extended
smoke_test_world_list.gd covering the non-joined entry point (11/11).
Full existing Godot smoke suite (18 files) and backend pytest (132)
still pass unchanged.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y2FESCaMXeJpC9gSctiEeD
