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/run_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // white-box tests reach unexported state (approved 2026-07-07)
 package game
 
 import (
@@ -39,6 +40,7 @@ func driveTurns(t *testing.T, g *RogueGame, n int) {
 // TestRunDownStairs stands the hero on the staircase and descends via the
 // '>' command through the real turn loop, then checks the level changed.
 func TestRunDownStairs(t *testing.T) {
+	t.Parallel()
 	// '>' is a free action (After=false), so it is followed by a paying
 	// rest ('.') to end the command() call; without a paying action the
 	// turn loop would spin forever on the auto-fed prompt input.
@@ -65,6 +67,8 @@ func TestRunDownStairs(t *testing.T) {
 // quit and death paths that normally show it now exit the process, so the
 // display is exercised through score() directly.
 func TestScoreRendersList(t *testing.T) {
+	t.Parallel()
+
 	g := New(Params{Seed: 1, Term: &testTerm{}})
 	g.Player.Purse = 100
 
@@ -90,6 +94,8 @@ func TestScoreRendersList(t *testing.T) {
 // The hero is fortified so no death exits the process (step 8), and the fixed
 // seed keeps it deterministic.
 func TestDeepPlaythrough(t *testing.T) {
+	t.Parallel()
+
 	g := New(Params{Seed: 4242, Wizard: true, Term: &testTerm{}})
 	g.startLevel()
 	g.prePlay()
@@ -155,6 +161,7 @@ func TestDeepPlaythrough(t *testing.T) {
 // and traps. The hero is fortified each turn so nothing exits the process,
 // and the fixed seeds keep it deterministic; the point is to surface panics.
 func TestTurnLoopCrashSweep(t *testing.T) {
+	t.Parallel()
 	// A generous mix of movement, search, and rest. The spaces between
 	// commands double as answers to any --More-- prompt (wait_for eats
 	// everything up to a space); without them one prompt would swallow the