fix(client): address PR #40 review — 13 suggestions

- Rename _insert to insert_state in main.gd (Hoshe #1)
- Add after_each() to test_bug_report_ring_buffer.gd for GameState
  cleanup on assertion failure (Hoshe #2)
- Add after_each() to test_insert_off_behavior.gd for stance/interaction
  restore on assertion failure (Hoshe #3)
- Fix assertion message: "unknown" → "unavailable" (Hoshe #4)
- Document memory ceiling of 60 JSON snapshots in ring buffer (Hoshe #5)
- Add precision warning for u64 rng_seed via JSON float (Hoshe #6)
- Promote _action_enum_to_wire to public action_enum_to_wire (Tyre #1)
- Add @warning_ignore for unused _tick parameter (Tyre #5)
- Document insert_active assumption for future no-insert characters (Tyre #4)
- Restructure OQ-07 decision amendments as bullet points (Tyre #7)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/tests/test_insert_off_behavior.gd

@@ -16,6 +16,13 @@ class_name TestInsertOffBehavior
 extends GdUnitTestSuite
 
 
+func after_each() -> void:
+	# Reset GameState fields mutated by tests to prevent cross-test leakage.
+	GameState.nearby_interactions = []
+	GameState.player_stance = "Walk"
+	GameState.insert_active = true
+
+
 # -- Helpers -------------------------------------------------------------------
 
 func _make_cursor() -> Node: