40250 classic W2: EntityStore data-layer only + net_world visibility (增量 50)

CLIENT-GAP-FIX §2.1/§2.3/§2.4/§2.5 (+ §2.2 steps 4-5):

- §2.1 two-layer model: EntityStore is data-only. Entries are created only by
  mut_spawn / mut_spawn_full / mut_spawn_main and removed only by mut_despawn /
  main-vid table clear. Every other mut_* now does find-or-return with a
  MT_NET_TRACE-gated debug log; no pending / replay buffer. Visibility moves to
  net_world.gd::_update_visibility() — per frame it walks client.get_entities()
  and mirrors is_main / AFFECT_SHOW_ALWAYS(bit 7) / IsWall(14201-14204) /
  planar-distance < CHAR_STAGE_VIEW_BOUND (200*100 cm), building a node on entry
  and fading + freeing it past +10 while keeping the data row (_fading guard).
  Gate is fail-open when the data layer is not queryable (no get_entities /
  _main_vid == 0 / no pos_cm) so existing fake-client tests are unaffected.
- §2.3 one overwrite rule: mut_spawn_full() does a clean whole-row value replace
  (m_ents[vid] = e), no preservation of prior move state on VID reuse; mut_spawn()
  now delegates to it. net_world._on_spawn destroys + recreates a node when the
  vid already has one; mount/dismount rebuild keeps the old global_position.
- §2.4 points bounds: mut_set_points() clamps counts > POINT_MAX_NUM (255) and
  zeroes the tail of a short snapshot; mut_set_point() rejects type >= 255.
- §2.5 field apply order + affect flags: new EntityStore::mut_affect_flags(vid,
  lo, hi) assembles v = lo | (hi << 32) and queues a dirty tick; mut_char_update
  guild/alignment/pk changes now also push Info. net_world._apply_field_updates()
  applies fields in the reference call order (NetworkActorManager.cpp:470).
- §2.2 steps 4-5: mut_char_info() / mut_shop_sign() drop the touch()-creates-
  entity path. Steps 1-3 (m_pending_actor two-packet merge) remain W1-owned.

Tests: ./build.sh Debug exit 0; ctest 16/16 (net.entity_store gains a §2.1
data-layer assertion block). New project/net_world_vis_test.gd for scene-node
visibility. GDScript regressions green: netbridge_test, gamescene_test,
netplay_test, p9_test, combat_fx_test, player_motion_test, net_world_vis_test.

Follow-up for W1: call mut_affect_flags(vid, affect_flag[0], affect_flag[1])
from classic_parser.cpp after GC_CHARACTER_ADD[2] / GC_CHARACTER_UPDATE
(mut_char_update has no affect param). wire_classic.h already has the wanted
static_assert on GCPoints.points.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014yvAPqPivoY7vmBbzgqK4W

extension/src/net/entity_store.h

@@ -481,6 +481,10 @@ public:
 	void mut_spawn_full(const Entity &e);
 	// summon / horse ownership (CLIENT-GAP §2.5); no-op if vid unknown.
 	void mut_ownership(uint32_t vid, uint32_t owner_vid);
+	// Affect bitset from GC_CHARACTER_ADD[2] / GC_CHARACTER_UPDATE, delivered as
+	// the two 32-bit wire words (CLIENT-GAP §2.5: v = lo | (hi << 32)). Queues a
+	// dirty tick so net_world re-mirrors the node; no-op if vid unknown.
+	void mut_affect_flags(uint32_t vid, uint32_t lo, uint32_t hi);
 	// Map background music (CLIENT-GAP §9.1). name is the resolved track id or
 	// path; volume < 0 means "server did not specify, keep current".
 	void mut_map_bgm(const std::string &name, float volume);