more refactor

CLAUDE.md

@@ -61,9 +61,9 @@ Root `Cargo.toml`: `members = ["kiln-core", "kiln-tui"]`.
 **`kiln-core/src/script.rs`** — Rhai scripting runtime:
 - `ScriptHost` — owns the Rhai `Engine`, the compiled scripts referenced by a board's objects (compiled once per name), a per-object persistent `Scope`, and a shared command queue. Built with `ScriptHost::new(&Rc<RefCell<Board>>)` (registers the API, compiles scripts, reports compile/unknown-script failures as `GameCommand::Error`; runs nothing).
 - Lifecycle hooks per object: `init()` (zero-arg) and `tick(dt)` (elapsed seconds as `f64`), both optional — detected via `AST::iter_functions()` by name and arity. Driven by `run_init()` / `run_tick(dt)`; runtime errors become `Error` commands, not fatal.
-- **Reads (direct):** scripts read through `BoardView` — a read-only handle (getters only, so read-only by construction) pushed into each scope as `board`, e.g. `board.player_x`, `board.player_y`, `board.width`, `board.height`. Each getter briefly borrows the shared `Board`.
+- **Reads (direct):** read getters (`player_x`, `player_y`, `width`, `height`) are registered directly on `Rc<RefCell<Board>>` (the `BoardRef` alias, exposed to Rhai under the type name `Board`) — getters only, so read-only by construction. A clone of the handle is pushed into each scope as the constant `Board`, so scripts write `Board.player_x` etc. Each getter briefly borrows the shared `Board`.
 - **Writes (command queue):** host fns `move(dir)`, `set_tile(n)`, `log(s)` push a `Command { source, kind: GameCommand }` (`GameCommand` = `Move(Direction)` / `SetTile(u32)` / `Log(LogLine)` / `Error(String)`) into a shared `Rc<RefCell<Vec<Command>>>`, drained by `GameState::take_commands` and applied after the batch. This is how scripts mutate without a `&mut GameState` borrow.
-- **Sender identity:** `source` (which object issued a command) rides the per-call **tag** — `run` calls `call_fn_with_options(...with_tag(object_index)...)` and the host fns read it via `NativeCallContext::tag()`. Scripts write `move(north)` without naming themselves; `north`/`south`/`east`/`west` are `Direction` constants in scope, and `impl From<Direction> for (i32,i32)` gives the delta.
+- **Sender identity:** `source` (which object issued a command) rides the per-call **tag** — `run` calls `call_fn_with_options(...with_tag(object_index)...)` and the host fns read it via `NativeCallContext::tag()`. Scripts write `move(North)` without naming themselves; `North`/`South`/`East`/`West` are `Direction` constants in scope, and `impl From<Direction> for (i32,i32)` gives the delta.
 - `GameState` (hence the `Engine`/`Scope`) is single-threaded / not `Send`; fine for kiln-tui.
 - **TODO in-code:** `Command.source` (and `ObjectRuntime.object_index`) are array indices into `Board::objects` — a stopgap that breaks under object spawn/destroy/reorder; should become a monotonically-increasing unique object id with objects keyed by it.
 
@@ -200,14 +200,14 @@ target_entry = "west_door"
 [scripts]
 greeter = """
 fn init() {                          # optional, run once at startup
-    log(`player at ${board.player_x}, ${board.player_y}`);   # read the world
+    log(`player at ${Board.player_x}, ${Board.player_y}`);   # read the world
     set_tile(2);                     # write: change my glyph
 }
-fn tick(dt) { move(north); }         # optional, run every frame; dt = elapsed seconds
+fn tick(dt) { move(North); }         # optional, run every frame; dt = elapsed seconds
 """
 ```
 
-Colors are `"#RRGGBB"` hex strings. `player_start` is a header field — the player is not a board cell. The `tile` field accepts either a single-character string (`tile = " "`) or an integer (`tile = 35`); both are valid and existing char-style map files continue to work. The grid multi-line string's leading newline is trimmed by TOML; trailing newline is handled correctly by `str::lines()`. Unknown archetype names produce an `ErrorBlock` cell and a logged warning. Script source lives in the `[scripts]` table (name → Rhai source); objects reference a script by `script_name`. Scripts may define optional `init()`/`tick(dt)` functions; they **read** the world through `board.*` (e.g. `board.player_x`) and **write** via host functions `move(dir)` (`dir` ∈ `north`/`south`/`east`/`west`), `set_tile(n)`, and `log(s)`.
+Colors are `"#RRGGBB"` hex strings. `player_start` is a header field — the player is not a board cell. The `tile` field accepts either a single-character string (`tile = " "`) or an integer (`tile = 35`); both are valid and existing char-style map files continue to work. The grid multi-line string's leading newline is trimmed by TOML; trailing newline is handled correctly by `str::lines()`. Unknown archetype names produce an `ErrorBlock` cell and a logged warning. Script source lives in the `[scripts]` table (name → Rhai source); objects reference a script by `script_name`. Scripts may define optional `init()`/`tick(dt)` functions; they **read** the world through `Board.*` (e.g. `Board.player_x`) and **write** via host functions `move(dir)` (`dir` ∈ `North`/`South`/`East`/`West`), `set_tile(n)`, and `log(s)`.
 
 ### Key design decisions