Re-vendor the canonical files from sneak/prompts at dd4027b (closes #112)

The shared files are fetched from sneak/prompts dd4027b, with this
repository's own entries after the shared content in .gitignore,
.editorconfig and .dockerignore.

Lint and tests are Dockerfile phases (golangci-lint v2.14.0, Debian Go
1.24.13) that the build stage depends on, and the Makefile targets call
the script/ entrypoints. make fmt also formats Markdown with prettier.

Fixes for the new lint findings: the auth cookie is always Secure, an
IRC connection's relay goroutine stops when the connection closes, and
repeated strings are constants.

Model: opus-5-5

internal/db/queries_test.go

@@ -987,11 +987,12 @@ func TestGetOperCount(t *testing.T) {
 	sid2, _, _, err := database.CreateSession(
 		ctx, "user2", "", "", "",
 	)
-	_ = sid2
 	if err != nil {
 		t.Fatal(err)
 	}
 
+	_ = sid2
+
 	// Initially zero opers.
 	count, err := database.GetOperCount(ctx)
 	if err != nil {
@@ -1023,23 +1024,25 @@ func TestGetOperCount(t *testing.T) {
 func TestWildcardMatch(t *testing.T) {
 	t.Parallel()
 
+	const hostmask = "nick!user@host"
+
 	tests := []struct {
 		pattern string
 		input   string
 		match   bool
 	}{
-		{"*!*@*", "nick!user@host", true},
+		{"*!*@*", hostmask, true},
 		{"*!*@*.example.com", "nick!user@foo.example.com", true},
 		{"*!*@*.example.com", "nick!user@other.net", false},
 		{"badnick!*@*", "badnick!user@host", true},
 		{"badnick!*@*", "goodnick!user@host", false},
-		{"nick!user@host", "nick!user@host", true},
-		{"nick!user@host", "nick!user@other", false},
+		{hostmask, hostmask, true},
+		{hostmask, "nick!user@other", false},
 		{"*", "anything", true},
-		{"?ick!*@*", "nick!user@host", true},
+		{"?ick!*@*", hostmask, true},
 		{"?ick!*@*", "nn!user@host", false},
 		// Case-insensitive.
-		{"Nick!*@*", "nick!user@host", true},
+		{"Nick!*@*", hostmask, true},
 	}
 
 	for _, tc := range tests {