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/scrolls.go

@@ -1,3 +1,4 @@
+//nolint:mnd // C-faithful literals; names hurt C-greppability (approved 2026-07-07)
 package game
 
 // scrolls.c — read a scroll and let it happen.
@@ -148,7 +149,8 @@ func (g *RogueGame) createMonsterSpot() (Coord, bool) {
 			// Or anything else nasty
 			if ch := g.Level.VisibleChar(y, x); stepOk(ch) {
 				if ch == Scroll {
-					if fo := g.Level.ObjectAt(y, x); fo != nil && fo.ScrollKind() == ScrollScareMonster {
+					if fo := g.Level.ObjectAt(y, x); fo != nil &&
+						fo.ScrollKind() == ScrollScareMonster {
 						continue
 					}
 				}