chore(lint): adopt canonical golangci-lint config

Replace .golangci.yml with the shared canonical config. The old
config's top-level linters-settings block was silently ignored under
the v2 schema, so the lll/funlen/cyclop/dupl thresholds now actually
apply. The four repo-specific disables (mnd, exhaustive, paralleltest,
testpackage) move out of the config into targeted in-code nolint
directives carrying their original approval dates, keeping the config
byte-identical to the canonical one.

Fixes surfaced by the stricter settings: t.Parallel() added to all 32
tests, 24 overlong lines wrapped or their comments tightened, tcell
control-code returns rewritten as character literals, dupl markers on
the identically-shaped item data tables, and two wsl_v5 defer cuddles.

No behavior changes. The repo has no golangci-lint version pin (no
Dockerfile or CI; make lint runs the host binary, currently v2.12.2),
so there was nothing to bump.

game/command.go

@@ -1,3 +1,4 @@
+//nolint:mnd // C-faithful literals; names hurt C-greppability (approved 2026-07-07)
 package game
 
 // command.c — read and execute the user commands.
@@ -794,6 +795,7 @@ func (g *RogueGame) call() {
 func (g *RogueGame) callTarget(obj *Object) (*ObjInfo, string, *string, bool) {
 	it := &g.Items
 
+	//nolint:exhaustive // C-faithful: only the cases C handled (approved 2026-07-07)
 	switch obj.Kind {
 	case KindRing:
 		return &it.Rings[obj.Which], it.RingStones[obj.Which], nil, true
@@ -815,7 +817,9 @@ func (g *RogueGame) callTarget(obj *Object) (*ObjInfo, string, *string, bool) {
 // callPrelude resolves the item's current name, reporting a previous
 // guess; ok is false when the item is already identified (command.c
 // call).
-func (g *RogueGame) callPrelude(op *ObjInfo, elsewise string, guess *string) (string, *string, bool) {
+func (g *RogueGame) callPrelude(
+	op *ObjInfo, elsewise string, guess *string,
+) (string, *string, bool) {
 	fromGuess := false
 
 	if op != nil {