Add BCE temporal tags to all documents; add temporal-dating steering doc

civilizations/roman-republic-and-empire.md

@@ -4,28 +4,28 @@
 # Roman Republic and Empire
 
 ## Overview
-Rome evolved from a small Italian city-state to a republic (509–27 BCE) and then an empire (27 BCE – 476 CE in the West) that dominated the Mediterranean world. Roman law, engineering, and governance profoundly shaped Western civilization.
+Rome evolved from a small Italian city-state to a republic (509–27 BCE) and then an empire (27 BCE – 476 CE in the West) that dominated the Mediterranean world. Roman law, engineering, and governance profoundly shaped Western civilization. @t[509 BCE..27 BCE]
 
 ## Key Facts
 - Region: Mediterranean basin, Western Europe, North Africa, Near East
-- Kingdom: ~753–509 BCE
-- Republic: 509–27 BCE
-- Empire: 27 BCE – 476 CE (Western), continued as Byzantine Empire in the East
+- Kingdom: ~753–509 BCE @t[753 BCE..509 BCE]
+- Republic: 509–27 BCE @t[509 BCE..27 BCE]
+- Empire: 27 BCE – 476 CE (Western), continued as Byzantine Empire in the East @t[27 BCE..476]
 - Capital: Rome; later Constantinople (from 330 CE)
 - Language: Latin
 - Writing: Latin alphabet
 
 ## Major Periods
-- Roman Kingdom (~753–509 BCE): Legendary founding by Romulus
-- Early Republic (509–264 BCE): Expansion in Italy, Conflict of the Orders
-- Late Republic (264–27 BCE): Punic Wars, civil wars, Caesar's assassination (44 BCE)
-- Principate (27 BCE – 284 CE): Augustus through the Crisis of the Third Century
+- Roman Kingdom (~753–509 BCE): Legendary founding by Romulus @t[753 BCE..509 BCE]
+- Early Republic (509–264 BCE): Expansion in Italy, Conflict of the Orders @t[509 BCE..264 BCE]
+- Late Republic (264–27 BCE): Punic Wars, civil wars, Caesar's assassination (44 BCE) @t[264 BCE..27 BCE]
+- Principate (27 BCE – 284 CE): Augustus through the Crisis of the Third Century @t[27 BCE..284]
 - Dominate (284–476 CE): Diocletian's reforms through the fall of the Western Empire @t[=476]
 
 ## Achievements
 - Roman law: Foundation of Western legal tradition [^1]
 - Engineering: Aqueducts, roads (~400,000 km network), concrete, the Colosseum
-- Pax Romana (~27 BCE – 180 CE): ~200 years of relative peace and prosperity
+- Pax Romana (~27 BCE – 180 CE): ~200 years of relative peace and prosperity @t[27 BCE..180]
 - Latin language and literature: Virgil, Ovid, Cicero, Tacitus
 
 ## Fall of the Western Empire