Mark stale projects with 🧊, remove archived entries, add Arcane (#1267)

- Add 🧊 marker for 113 stale projects (2+ years inactive)
- Remove 4 archived repos (Centurion, notary, Minio, docker-ls)
- Remove 1 broken link (docker-lock / safe-waters)
- Add Arcane to the Web section
- Replace 💲 with 💴 across README and tooling
- Add 🧊 (MarkerStale) support to Go parser/linter
- Update CONTRIBUTING.md, PR template, issue template, and AGENTS.md

Closes #1260, relates to #1188, #1255

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

internal/linter/fixer.go

@@ -39,9 +39,11 @@ func FormatEntry(e parser.Entry) string {
 		case parser.MarkerAbandoned:
 			markers = append(markers, ":skull:")
 		case parser.MarkerPaid:
-			markers = append(markers, ":heavy_dollar_sign:")
+			markers = append(markers, ":yen:")
 		case parser.MarkerWIP:
 			markers = append(markers, ":construction:")
+		case parser.MarkerStale:
+			markers = append(markers, ":ice_cube:")
 		}
 	}
 	if len(markers) > 0 {