Refresh ARCHITECTURE.md Part 2 for the post-refactor design

Part 2 was written as a design sketch before the port was implemented and
refactored, so much of it described the planned code rather than the final
code. Updated the RogueGame/Stats/Object/Flags/Level sketches to the current
names and types (typed ObjectKind, DiceSpec, split o_arm fields, step-1 flag
names, TrapCount, Level list methods); rewrote §4.7 to say the static tables
now live on the per-game gameData struct (no package globals); noted the
daemon and effect handler tables (step 7), the MessageLine extraction (step 6),
the Terminal interface, the flat gob SaveState, and the New(Params) +
os.Exit-on-game-over design (step 8). Added §7.1, a C-name → Go-name rename
table, and a README note about the make targets. Docs only.

README.md

@@ -73,8 +73,12 @@ cmd/rogue/   the executable
 ```
 
 The engine package is fully headless-testable: `go test ./game/` runs scripted
-game sessions, dungeon-generation golden checks, and an RNG compatibility test
-against the original C generator.
+command sequences, dungeon-generation golden checks, and an RNG compatibility
+test against the original C generator.
+
+For development, the `Makefile` wraps the toolchain: `make fmt` (gofmt +
+prettier), `make lint` (golangci-lint), `make test`, and `make check` (all
+three).
 
 ## License