Add bump-to-attack, death and a sim event queue

A step onto an occupied tile is now an attack: the geometry rule is checked
against terrain only and the target tile decides between move and bump.
Entities carry an attack stat; at zero hp they are removed. The sim reports
Attacked/Died through an event queue the game drains after every movement
window — the seam for sound, log, camera effects and spawns. Click-to-move
treats an occupied goal as a target but detours around entities in the way;
the player's death ends the game.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

notes/roadmap.md

@@ -58,13 +58,23 @@ crate's `tick`/`set_action` interface is the seam a server could be wrapped arou
       approach, τ = 120 ms), snapping only to whole pixels at render time (and outright
       on teleport-sized corrections). The viewport renders with sub-tile offsets
       (31×31 tile pass + right-strip clip).
-- [x] Entity blocking: `World::blocked` (solid tile ∨ out of world ∨ occupied) is the
-      one predicate the sim's `entity_tick` and the pathfinder share. Intents execute
-      in id order, so the player (id 1) wins a contested tile deterministically.
+- [x] Entity blocking: `World::solid` (collidable tile ∨ out of world) and
+      `World::blocked` (solid ∨ occupied). The sim checks the geometry rule against
+      `solid` and resolves the target tile itself; the pathfinder plans with `blocked`.
+      Intents execute in id order, so the player (id 1) wins a contested tile
+      deterministically.
 - [x] First NPC: `EntityKind { Player, Npc }` on `Entity`; `Sim::think` runs before
       every movement window and schedules a random king move for each NPC one window
       in four (seeded xorshift in `Sim`). Sprite = tile 1 in `entities.png` (a hen from
       the Mini-Medieval pack). One is spawned at (6, 6) in `Game::start`.
+- [x] Bump-to-attack and death: the geometry rule is checked against terrain only
+      (`World::solid`); an entity on the target tile turns the step into an attack
+      (`Entity::attack` damage, `hp` saturating). At 0 hp the entity is removed. The
+      sim reports both through its event queue — `sim::Event { Attacked, Died }`,
+      drained by the game with `Sim::take_events` after every window — which is the
+      seam for sound, message log, camera shake, spawns. Player death quits for now.
+      Click-to-move treats an occupied goal as a target (route ends in a bump) but
+      walks around entities in the way; keyboard steps always bump.
 - [x] Entity interpolation: per-id lerp table (`EntityLerp` in `game.rs`) — previous/current
       tile plus a clock, rendered as a pixel lerp over one movement interval. Jumps of
       more than one tile (Chebyshev) snap. Purely cosmetic; game logic keeps using the
@@ -106,7 +116,12 @@ budget model goes once there are enough NPCs to need it. The action-point model
 06 is still pending and only matters once NPC speeds should differ.
 
 - [x] `EntityKind::Npc`, `Sim::think` scheduling intents through the same intent table
-- Bump-to-attack: a step onto an occupied tile becomes an attack instead of a refused move
+- [x] Bump-to-attack, death, `Event` queue
+- Stats beyond `hp`/`attack` (defense, speed) as plain fields; a `Stats` substruct once
+  they crowd `Entity`. No ECS until entities actually differ in *which* components they
+  carry — see the discussion of 2026-09-19.
+- NPC reactions (flee when hit, aggro on the player) — `think` would need to see the
+  previous window's events; today the game drains them right after `step`
 - Per sim-tick: distribute a fixed `think_budget` across entities ordered by player proximity
 - Complex entities consume more budget; simple ones less. Loop breaks at zero — natural load shedding.
 - No framework. No trait objects yet. A match on `EntityKind` is fine.