Working about pathfinding

GAME_STATE_ARCHITECTURE.md

@@ -340,8 +340,9 @@ The player state remains campaign-level and survives location changes.
 
 ## Save and Load Schema
 
-Authoritative persistence uses one strict, versioned schema. `schemaVersion` is
-required and unsupported versions are rejected rather than migrated. A
+Authoritative persistence currently uses strict schema version `5`.
+`schemaVersion` is required and unsupported versions are rejected rather than
+migrated. A
 single-player save is a separate versioned envelope containing `networkState`
 (the authoritative `GameState` JSON) and `localState` (the client-local location
 map). Lockstep sends that authoritative document only in `initial_state`; later
@@ -351,6 +352,9 @@ messages contain numbered command bundles.
 - Locations are keyed by location ID.
 - Each location stores NPC and interactive-object state in ID-keyed objects.
 - Pending interaction targets and character references use stable IDs.
+- Character navigation persistence includes waypoints, actual previous-tick
+  movement, blocked/retry state, the blocker ID, and the NPC cooldown sequence
+  and cursor.
 - Immutable content such as meshes, initial taxi configuration, and object
   definitions is reconstructed from campaign configuration.
 - Configuration is loaded first and mutable saved state is overlaid in place.
@@ -478,12 +482,33 @@ cmake --build proj-windows/build --config Debug --target ShadowOverBishkekDemo -
   auxiliary-state synchronization without making `Game` a server friend.
 - Empty player maps are valid. Player-specific interactions remain inactive until
   a player entity is added.
-- Pathfinding priority queues use cell index as a stable secondary key.
+- Pathfinding uses integer cardinal/diagonal costs and compares priority,
+  accumulated cost, then cell index.
 - Gameplay randomness must be seeded and serialized; the `random_device` battle
   bot is disabled for multiplayer sessions.
 - A lockstep compatibility fingerprint must match before the client accepts the
   initial state.
 
+### Dynamic Navigation Occupancy
+
+`LocationGameState` is the authoritative boundary for character-aware planning.
+It collects enabled, living, stationary players and NPCs in stable ID order and
+passes their positions and collision radii to `LocationNetworkState` and
+`PathFinder`. The requester is excluded; moving characters are transparent to
+planning. “Moving” here means actual previous-tick displacement
+(`movedLastTick`), not merely owning an active path, so visually stalled
+characters remain planning obstacles. Route planning uses full avoidance radii;
+the movement guard uses smaller contact radii.
+
+Every character movement step is guarded against stable-ID-ordered reservations
+initialized from tick-start geometry. Accepted steps update their reservation
+before later characters advance, preventing two movers from ending a tick
+overlapped. Blocked/retry counters, cooldown sequence/cursor, and blocker ID are
+serialized character state. Head-on players and bots cancel their commands;
+NPCs retain their targets and consume the next deterministic, ID-shuffled
+cooldown before replanning. Static navigation topology changes route through
+the same centralized replanning path.
+
 ## Main Files
 
 - `src/GameState.h` / `src/GameState.cpp` — aggregate state and top-level persistence.
@@ -502,7 +527,7 @@ cmake --build proj-windows/build --config Debug --target ShadowOverBishkekDemo -
   broadcasting, buffering, and replica advancement.
 - `src/Game.h` / `src/Game.cpp` — application host, campaign lifecycle, and runtime wiring.
 - `src/Location.h` / `src/Location.cpp` — loaded location runtime, command routing,
-  interactions, collisions, scripts, and presentation-event consumption.
+  interactions, scripts, and presentation-event consumption.
 - `src/Character.h` / `src/Character.cpp` — passive character presentation resolving
   immutable `CharacterState` snapshots by stable ID.
 - `src/CharacterState.h` / `src/CharacterState.cpp` — deterministic character